Microcosm

The build you posted looks a lot more human-centric than triform.

(If you prefer a human build with just a little triform flare, disregard my advice below).
If I was going to keep your build generally the same but make it more triform oriented, here is what I would do:

Hero Plan by Mids' Hero Designer 1.803
http://www.cohplanner.com/

Click this DataLink to open the build!

Graui 3.0: Level 50 Science Warshade
Primary Power Set: Umbral Blast
Secondary Power Set: Umbral Aura
Power Pool: Concealment
Power Pool: Speed
Power Pool: Leaping

Hero Profile:
Level 1: Ebon Eye -- Dev'n-Hold%(A)
Level 1: Absorption -- Aegis-Psi/Status(A)
Level 2: Gravity Shield -- S'fstPrt-ResDam/Def+(A)
Level 4: Gravimetric Snare -- GravAnch-Immob(A), GravAnch-Immob/Rchg(5), GravAnch-Acc/Immob/Rchg(50), GravAnch-Acc/Rchg(50), GravAnch-Immob/EndRdx(50)
Level 6: Dark Nova -- GSFC-Build%(A)
Level 8: Shadow Blast -- Dmg-I(A), Dmg-I(21), Dev'n-Dmg/EndRdx(39)
Level 10: Grant Invisibility -- LkGmblr-Rchg+(A)
Level 12: Sunless Mire -- Oblit-Dmg(A), Oblit-Acc/Rchg(15), Oblit-Dmg/Rchg(15), Oblit-Acc/Dmg/Rchg(17), Oblit-Acc/Dmg/EndRdx/Rchg(17)
Level 14: Shadow Cloak -- LkGmblr-Rchg+(A)
Level 16: Penumbral Shield -- S'fstPrt-ResKB(A)
Level 18: Gravity Well -- BasGaze-Acc/Hold(A), BasGaze-Rchg/Hold(19), BasGaze-EndRdx/Rchg/Hold(19), BasGaze-Acc/EndRdx/Rchg/Hold(27), Dmg-I(31), Dmg-I(37)
Level 20: Black Dwarf -- HO:Ribo(A), HO:Ribo(37)
Level 22: Stygian Circle -- Efficacy-EndMod/EndRdx(A)
Level 24: Nebulous Form -- Winter-ResSlow(A)
Level 26: Hasten -- RechRdx-I(A), RechRdx-I(27)
Level 28: Gravitic Emanation -- Amaze-Stun(A), Amaze-Stun/Rchg(29), Amaze-Acc/Stun/Rchg(29), Amaze-Acc/Rchg(31), Amaze-EndRdx/Stun(31)
Level 30: Inky Aspect -- Stpfy-Stun/Rng(A), Stpfy-Acc/Stun/Rchg(43), Stpfy-Acc/Rchg(43), Stpfy-EndRdx/Stun(45), Stpfy-Acc/EndRdx(46), Amaze-ToHitDeb%(46)
Level 32: Dark Extraction -- ExRmnt-Acc/Rchg(A), ExRmnt-EndRdx/Dmg/Rchg(33), ExRmnt-Acc/Dmg/Rchg(33), ExRmnt-Acc/Dmg(33), S'bndAl-Dmg/Rchg(34), S'bndAl-Build%(40)
Level 35: Stealth -- LkGmblr-Rchg+(A)
Level 38: Eclipse -- GA-RechRes(A), TtmC'tng-ResDam/Rchg(39), Aegis-ResDam/Rchg(39), ImpArm-ResDam/Rchg(45)
Level 41: Invisibility -- LkGmblr-Rchg+(A)
Level 44: Unchain Essence -- Posi-Dmg/Rchg(A), Posi-Dmg/Rng(45), Posi-Dmg/EndRdx(48), Posi-Acc/Dmg(48), Posi-Dam%(48)
Level 47: Stygian Return -- Heal-I(A)
Level 49: Combat Jumping -- LkGmblr-Rchg+(A)
------------
Level 1: Brawl -- Empty(A)
Level 1: Sprint -- Clrty-Stlth(A)
Level 2: Rest -- Empty(A)
Level 1: Dark Sustenance
Level 1: Shadow Step -- TSM'n-Rng(A)
Level 10: Shadow Recall -- Empty(A)
------------
Level 6: Dark Nova Bolt -- Empty(A)
Level 6: Dark Nova Blast -- Apoc-Dam%(A), Apoc-Dmg(25), Apoc-Dmg/Rchg(25), Apoc-Acc/Dmg/Rchg(40), Apoc-Dmg/EndRdx(40)
Level 6: Dark Nova Emanation -- Posi-Dam%(A), Posi-Acc/Dmg(7), Posi-Dmg/EndRdx(7), Posi-Dmg/Rchg(9), Posi-Dmg/Rng(9)
Level 6: Dark Nova Detonation -- Posi-Dam%(A), Posi-Acc/Dmg(11), Posi-Dmg/EndRdx(11), Posi-Dmg/Rchg(13), Posi-Dmg/Rng(13)
Level 20: Black Dwarf Strike -- C'ngImp-Dmg/EndRdx(A), C'ngImp-Dmg/Rchg(36), C'ngImp-Acc/Dmg(36), C'ngImp-Acc/Dmg/EndRdx(36), C'ngImp-Dmg/EndRdx/Rchg(37)
Level 20: Black Dwarf Smite -- Hectmb-Dam%(A), Hectmb-Dmg/Rchg(42), Hectmb-Acc/Dmg/Rchg(42), Hectmb-Acc/Rchg(42), Hectmb-Dmg/EndRdx(43)
Level 20: Black Dwarf Mire -- Oblit-Dmg(A), Oblit-Acc/Dmg/EndRdx/Rchg(3), Oblit-%Dam(3), Oblit-Acc/Rchg(5), Oblit-Dmg/Rchg(21)
Level 20: Black Dwarf Drain -- Hectmb-Dmg(A), Dct'dW-Heal/EndRdx(23), Dct'dW-EndRdx/Rchg(23), Dct'dW-Heal/Rchg(34), Dct'dW-Heal/EndRdx/Rchg(34), Dct'dW-Heal(46)
Level 20: Black Dwarf Step -- EndRdx-I(A)
Level 20: Black Dwarf Antagonize -- Zinger-Dam%(A)

The whole fitness pool is pretty lackluster on a triform, so I replaced it with LotG mules. Dwarf was woefully underslotted, while iffy powers like dark detonation were putting you over the set bonus cap in some cases. Stygian Circle gives most of your health back from just one enemy unslotted, so slotting it with a heal set is not very helpful; however, it does not do the same endurance-wise, so in the interest of saving slots I did the most economical thing with the base slot. Dark Nova Blast needed some love too.

It's extremely bogus that khelds can't pick patron powers; they aren't epic pool powers and thus don't conflict with the dev mantra that "khelds are epic pools." They should get the same ppp's as SoA.

IMO Leviathan patron is still the best choice for a stalker, especially one that can softcap through its secondary. Waterspout with an achilles -res and hibernate are both extremely good, and taking the patron pet is not a bad idea if you can figure out how to use it.

They're best on classes that already have pets and can slot multiple pet uniques to help their survival. They're next best for Stalkers as they can improve your crit rate like a teammate. Obviously builds with the +recharge to keep them perma benefit from them more. If they do actually stay alive, they can contribute a good bit of single target or AoE damage.

I agree with Tangler as to the best pets and why.

HISTORICAL

HISTORICAL, NO LONGER APPLICABLE

Extreme Builds' Single Target chain:

After a bunch of number crunching and a little bit of testing of some strange things, I have found a chain that should allow my current build to go quite far past the 250 single target dps range, conservatively. Solo. Yes, that's right, from Electric Melee. About 67 of that is from the patron pet (which is also increasing the crit rate by 3%). It's entirely possible that I messed up some calculation somewhere, but regardless there is a little oddity of this combo that helps out a ton. I alluded to it in the main post, but I'll go ahead and give you the chain as I currently have it.

(Waterspout referred to as WS, Caltrops to CT, Chain Induction CI, Jacob's JL, Charged Brawl CB, Lightning Rod LR, Assassin's Shock AS, Build Up BU)

WS(/CT)->BU->LR->AS->(CI->CB->JL)->CB->CI->CT(/WS)->JL->CB->(CI->CB->JL->CB)*3->repeat

Whenever you come across a WS(/CT) combo and Water spout is not recharged, use Caltrops.

Why is this so great? It's the built up AS in there, along with -res procs in Waterspout and Jacob's Ladder. "But, Micro, I can placate->AS on many Stalkers." Look again; there is not placate in that chain. In fact, I don't have placate in my build. Waterspout, Caltrops, and Lightning Rod are all summoned pets, and as such do not break hide, or keep you from reentering hide. As long as more than 8 seconds passes between your last normal attack and the moment Assassin's Shock lands, you will reenter hide and pull off the AS. (This, of course, depends on you not being hit during those 8 seconds as well, but for a softcapped Stalker with the knockup/down of Waterspout and Lightning Rod, this is pretty easily done). Adjusting for arcanatime, Waterspout (or Caltrops) and Buildup take 1.32 seconds to activate each, LR takes 2.772, and AS takes 3.168. Add that up for 8.58 seconds, and voila: hidden status with full Assassin Shock. The only time you're not directly doing damage there is activating Build Up, for a grand total of 1.32 seconds. Waterspout and Caltrops both do some good damage over their duration for their required 1.32 seconds of activation, and Lightning Rod is one of the set's best dpa attacks as well.

This is why Electric Melee is superior on Stalkers, especially the /Nin variety.

Edit: Had the wrong activation time for AS :S

Also, something I forgot, Stalkers need to be given Shield defense. If any of the melee ATs needs an extra TAoE in their secondary, it's Stalkers. Remove the taunt effect from Against All Odds, and replace True Grit with Hide (at the moment +hp powers are pretty lame for stalkers anyway).

The reasoning that it's not a thematic fit for Stalkers is complete BS. They gave us freaking Neon Lights armor (electric), and since when does having extreme willpower, super reflexes, or a high regeneration rate make you invisible?

EDIT: And now that I've read the whole thread, I'd like to add my support for the following along with my other suggestions ('cept maybe raise the hp a little still):

'tis why I said it, sir.

Edit: Upon second read, I have a minor nitpick, though I might be wrong. Mids and Tomax are both saying the Dwarf Mire is the same radius as the Human: 15 feet. The Dwarf Mire does look bigger, but I'm not sure it really is.

I would actually recommend against the MFing Warshade, much as I love it, as it becomes so incredibly powerful in later levels, at which point the OP would be just about to retire the char.

(Oops, disregard)

No time to read the entire thread (really no time), but I want to weigh in.

Firstly, Scrapper Build Up should be lowered to 80% dambuff to bring it in line with other versions; Blasters should be the only AT that gets a 100% dambuff from Build Up. Sorry, but there is no reason balance-wise, cannon-wise, rp-wise, or jimmeny cricket-wise that Scrappers magically get the 100% buff.

As far as actual Stalkers go:

Electric melee is beautiful as is; Spines is also good. IMO Claws and Dual Blades are both good enough as well, though I miss follow up.
The biggest problem for the rest of the sets, as I see it, is the lack of AoE effectiveness.

-The two sword sets should have their current AoE attack (Flashing Steel and Slice) swapped for the more powerful ones that come later in the Scrapper set (Lotus Drop and Whirling Sword). Getting the more powerful attack earlier than Scrappers is balanced by the fact that you still are only able to get one of the two, but this should increase your overall AoE damage output. The attacks are mostly of the same type and slot the same sets, so no problem there. (Also, while not necessary, I would like to see the sword tier 9's crit-from-hidden chance changed to the single target 100%; these are really single target attacks that happen to have a chance to hit multiple enemies, not true AoE's like Jacob's Ladder or Shadow Maul, and as such they should get the single target crit chance).

-Dark Melee: remove Build Up and give the set a copy of Soul Drain tagged to not break hide (like the changes coming for dark armor) or alert enemies (like World of Confusion's damage ticks). This gives the set back a smidge of AoE (actually almost as much as the Scrapper/Brute version) and some of its uniqueness, while it is not overpowered because you cannot spam Soul Drain. Also makes the set more desirable because you could actually get multiple built up Assassin's Eclipse attacks off during the length of Soul Drain, again not over powered because the damagebuff effect is generally lower than an actual Build Up's.

-Martial Arts and Energy Melee: a set with no AoE is ludicrous in PvE. Both of these sets have a stun attack (minor damage) that should be replaced with the AoE attack in other variants of the set (Dragon's Tail and Whirling Hands respectively). A small chance to disorient could be added to either or both so that no one feels they have lost anything, and to make sure stun sets are still slottable with the addition of PBaoe sets. This would give these powersets the same AoE capabilities as Scrapper and Brute versions, while not really losing anything.

Doing all of that would ameliorate the AoE disparity sufficiently, in my opinion. Otherwise, the problem that Scrappers do more damage is generally balanced now by the scaling crit chance on teams (and we are hopefully changing Build Up's buff as well) which makes Stalkers pull ahead. We are left with the problem of hp cap disparity; you cannot say that the Stalker gimmick of Assassin's strike is the balance here because it is usually just that: a gimmick. In most cases (PvE), you will do more damage by just continuing your single target chain than by stopping to Build Up-->Placate-->AS. So it is consigned to being beneficial only against certain problem enemies. That makes it pretty much the same as a good mez. That Sapper over there? Well I can AS it or the dom can hold it, either way it's no longer a problem, but the Dom takes less time to neutralize it. That is not worth a lower hp cap, especially considering some secondaries lose effectiveness because they so easily go over the cap (looking at you, Energy Aura).

Before, I would have said the hp thing was balanced by the fact that Stalkers got things like Shadow Meld, but now that Scrappers are getting that too I cry foul. Stalkers are about to be simply inferior, and I would pretty much only play one for the exception of a set that is Stalker Electric Melee.

This guide receives Microcosm's stamp of approval. So much that is good in this guide I just cannot comment on it all.

You might want to add a link to Joe's bind sticky in the Kheld forum.

Also, for the tough bosses thing, if you're fighting really tough stuff like EB/AV's in dwarf and need to pop down to eclipse, it is wise to watch for the knockdown that the dwarf punches occasionally do and shift down to use that brief window to safely buff.