Well, here's my first time using one of the Hero builders. This'll give a breakdown of what powers I bought when, but ignore the slotting in the fine details. I seriously used Invention Origins (Trap of the Hunter, Impeded Swiftness, and Karma) over the past 10 or so levels, particularly the Damage Procs for Snare Arrow and Glue Arrow (both of which did more damage than my "best" actual attack, as sad as that is to say). I only did the builder up to 36 or so, because that's the ultimate goal for me: A boy, his fire demon, and a very flammable oil slick.
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Name: Kaijukore
Level: 38
Archetype: Mastermind
Primary: Ninjas
Secondary: Trick Arrow
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01 => Entangling Arrow ==> Acc(1),Immob(3),Acc(3),Acc(13)
01 => Snap Shot ==> Dam(1),Dam(19)
02 => Aimed Shot ==> Dam(2),Dam(5)
04 => Glue Arrow ==> Slow(4),Slow(5),Slow(7),Rech(11),Rech(11),Rech(13)
06 => Flash Arrow ==> ToHitDeBuff(6),ToHitDeBuff(7)
08 => Combat Jumping ==> DefBuff(8),DefBuff(9),DefBuff(9)
10 => Ice Arrow ==> Acc(10),Hold(25),Hold(25),Acc(34),Hold(34)
12 => Hurdle ==> Jump(12)
14 => Fistful of Arrows ==> EndCost(14),EndCost(15),Dam(15),Dam(19)
16 => Stealth ==> DefBuff(16),DefBuff(17),DefBuff(17)
18 => Swift ==> RunSpd(18)
20 => Stamina ==> EndMod(20),EndMod(21),EndMod(21)
22 => Acid Arrow ==> Acc(22),Acc(23),DefDeBuff(23),DefDeBuff(31),DefDeBuff(33),Rech(33)
24 => Train Ninjas ==> EndCost(24)
26 => Oni ==> Dam(26),Dam(27),Acc(27),Dam(31),Acc(31),Acc(33)
28 => Smoke Flash ==> EndCost(28),EndCost(29),EndCost(29)
30 => Disruption Arrow ==> EndCost(30)
32 => Kuji In Zen ==> EndCost(32),EndCost(34)
35 => Oil Slick Arrow ==> Rech(35),Rech(36),EndCost(36),EndCost(36)
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01 => Sprint ==> Empty(1)
01 => Brawl ==> Empty(1)
02 => Rest ==> Empty(1)
By the by, the reason Enlighten Ninja (the level 32 thing) is got endurance reduction slotted twice in it is that, even though I only have one pet....if it dies, I immediately resummon a new one in combat and enlighten it while it's already starting to engage the enemy. Certain powers became much more useful later on, particularly Ice Arrow when I started meeting large scary werewolves that were immune to slow and immobilize...the two things my build used to survive as well as it did.
Since I said I'd mention it, the thing that kept me from getting faceplanted all the time was simple crowd control. So there's no real secret there. With Flash Arrow you can pull very, very well....with glue and snare you can use corners to split up incoming mobs. Ice Arrow was really used as yet another Immobilize (rather than a hold, which is what it is) up until the late twenties when those dame wolves started showing up regularly.
The Oni turned out to be a great pet for my playstyle. While it has some great fire katana attacks, it's a dominator that likes range and immobilizes/holds just like me. Plus, unlike me, it actually does damage.
I know a few people are doing this as well...I'll be curious to see how you guys design your petless little monsters and, if you get it, how the top tier pet works out for you.
I am a little sad that I have a pet now and don't quite get the "OMG what the hell?" responses that I used to, but this toon has really turned into my favorite. I think its because of the adrenalin/panic rush you get when you keep coming close to dying. Oh and the other secret to being the last man standing during a near team-wipe? Hurdle+Combat Jumping makes you the speediest jumper around. Considering how you should never be in melee (remember, you're really squishy as a mastermind without meatshields) this means that when things go sour you have an escape velocity that isn't suppressed if someone hits you, unlike superspeed, superjump, or fly. It also means that you can literally jump up into the rafters on any stage that has them. Using the environment is your friend. Besides corners, most stages (particularly arachnos bases) have great ceilings/walls for strategic plinking/debuffing from relative safety.
Ok I'll quit rambling. Thanks for listening and thanks again for proposing this challenge. Was a blast. And I have a feeling that Kai is going to be my first level 50, as sick as that sounds.
-jared
PS: If you do make a petless mastermind, you WILL surprisingly be able to find a team with a lot of ease. I put "No Pets. Sorry" in my search description and I still got speedily invited to teams whenever I logged in. I think people have a morbid fascination with builds with a deathwish...though eventually some teams just work. This particular toon formed a duo with a stalker that was golden, for instance. Only a handful of times did people go OMG GET SOME GOD DAMN PETS and, even then the rest of the team was cool with it. If you're playing your Blastermind right, people will SEE what you're doing. Debuffs, Shields, or whatever your secondary is becomes vital, and your teammates usually benefit just like your missing minions would have. With no pets you're free to get more Secondaries...and the seduction of Leadership pool powers just isn't there...so you ending up being a mastermind with more secondary powers than most folks have seen in-game. Hell, last night our team had a great argument concerning which was more useless: Me and my (now) one-pet build or a full compliment of Robots Mastermind who did nothing but stay out of combat while using Invisibility while his minions did all the work. Apparently the 2nd one [censored] off more players than a debuff-crazy kamikaze MM. Go figure.
heh congratz on completeing your ironman challenge 
Can't imagine life without my Bots to be honest, the respec trial was hell WITH them let alone without (30-31 at the time) although there were useful for absorbing the inital alpha strike from a large group of vines.
Now fully slotted with SO's (foolishly i moved from TO's to DO's with my free respec, not realising i could have been buying SO's instead...i'm such a noob) they're heavy dealing damage machines.
Can't imagine them not being there, but you proved it could be done
Badge Earned: Wing Clipper
A real showstopper!
Well, I officially can no longer say that I play a petless mastermind. The evidence:
Click here to see what I've been waiting to see for what feels like an eternity
Yep, I finally have ONE pet.
Well, I didn't really do the challenge because you're not supposed to team, but I'm still stupid happy. (If you don't what I'm talking about, check out the "Mastermind Disarmed" thread where you can see someone introduce me to the idea and, well, the horror involved). My goal was to get a petless Ninja/Trick Arrow Mastermind to level 26. I played solo early on (to make sure I could) and started really teaming regularly around level 13 or so (Goldbrickers are a Blasterminds Kryptonite, apparently) as it got too difficult to solo. Around level 19 I got pretty discouraged as the difficulty ramped up again. But, with the double xp weekend....struck me as a good time to give my petless mastermind a chance again. So, from level 19 I just reached that faithful level where I get the Oni. So yeah. I'm just posting this because I'm pretty happy that I was able to survive as much as I did. I'll post the build and all that because I know other folks are giving other petless builds a chance. And also I can explain exactly why Kaijukore was the last man standing on more than one near-wipeout (and no the answer is NOT I stood by the door and leeched). Well, I'll do it later because right now I need some sleep.
Thanks everyone who supported me in game (not having to worry about infamy was a godsend) and, well, this was a blast.
-jared
Oh and here's the highlight of my marathon:
No caption is necessary for this