Notice: As of this writing, I am only 22. In beta, I was only 28. Some of this will be based on experience with MMs specifically, and some will be generalizations based on my experiences with CoH.
The Mastermind AT is completely unique in the CoH/CoV universe. No other AT gets pets so early, so many pets, or such nuanced control over their pets. In fact, the experience is so different; most people don't even call what Masterminds use pets. They are called minions or henchmen. We will be using henchmen here. Now to the specifics.
Robotics: An Overview
In general, your bots will share a few characteristics. They will have a resistance to lethal/psionic/cold damage. They will have a resistance to sleep/fear/disorient effects. They prefer ranged, and will use energy based attacks. Like all other MMs, you have three henchmen classes, and two upgrade powers. The upgrade powers are called Equip Robot and Upgrade Robot. Your henchmen are as follows:
Battle Drone: Your basic expendable battle bot. They can be quite unintelligent, and will often run to melee for no apparent reason. They have Super Leap as an inherent power. You get your second bot at 6 and your third at 12. They start with two powers:
<ul type="square">[*] Ranged Blast (Ranged, Energy)[*] Smash (Melee, Smashing)[/list]After the initial upgrade, they gain just one ability:
<ul type="square">[*] Heavy Laser Burst (Ranged, Energy/Smashing) BI: 1.78 1.14[/list]After the final upgrade, they gain:
<ul type="square">[*] Full Auto Laser (Ranged, Energy)[/list]
Protector Bot: The little defender that could. Your protector bots are perfectly capable offensively, but their primary usefulness to you will be their defender style abilities. You get your second bot at 24. They start with two powers:
<ul type="square">[*] Force Bubble (+DEF(All))[*] Ranged Blast (Ranged, Energy)[/list]After the initial upgrade they gain two abilities:
<ul type="square">[*] Limited Repair (Heal Bot) This is not the full heal of Repair in the bot line, but a much more limited heal.[*] Heavy Laser Burst (Ranged, Energy/Smashing)[/list]After the final upgrade, they gain:
<ul type="square">[*]Photon Grenade (Ranged AoE, Disorient, Smashing)[*]Seeker Drones These Seeker Drones will follow your bot until they detect an enemy and then they will zero in on their targets and detonate on impact. The small explosive flash of energy does only minor damage, but the concussion can weaken foes. Affected targets will have reduced Damage, Accuracy and Perception and may even be Disoriented for a short while. Your bot can only ever have Two Seeker Drones out at one time and they can be destroyed by its foes.[/list]
Assault Bot: This mammoth bot is literally a killing machine. 'Nuff said. It starts with one power:
<ul type="square">[*] Plasma Blast (Ranged, Energy)[*] Smash (Melee, Smashing)[/list]The initial upgrade grants two new abilities:
<ul type="square">[*] Flamethrower (Cone, Fire)[*] Dual Plasma Blast (Ranged, Energy)[/list]After the final upgrade, they gain:
<ul type="square">[*] Swarm Missles[*] Incendiary Swarm Missles[/list]
A note about bot control: It appears that bots have two separate path finding algorithms. One for "Attack My Target" and one for "Goto" or "Follow". The ATM pathfinding will cause you nothing but problems. You should always use Follow or Goto to place your bots before activating AMT.
A second note about bot control: Like a bunch of newbs, if you throw your bots in a room on Aggressive Mode, and don't tell them who to attack, they will all pick different targets, sometimes from multiple spawns, they will switch targets randomly, and they will take forever to finish. This is a good way to die. I suggest ALWAYS using AMT for target selection.
Now to the build. My build is centered on one ideal: Let my bots do the fighting. All of it. I don't take a single attack. There are just too many good buffs and debuffs. Buffs and debuffs are what I like to call a Force Multiplier. A defender running Assault solo is great, and I'm sure he likes that 12% buff. But when a lvl26 MM runs it, she gets her Assault bonus times SIX. I am of the opinion that given a choice between an attack and a buff/debuff, there is NO choice. With that said, lets move on.
LEVEL 1 POWER CHOICES:
Robotics: Battle Drone. This is obvious. Take it and use it. I slot as follows: 1 Accuracy 3 Damage and 1 Knockback. If you plan on teaming with a lot of melee types, you could easily drop the knockback slot and apply it elsewhere.
Dark Miasma: Twilight Grasp. No choice here. But its a nice power. If you are near your bots, as you should be with this build, they will all get a nice heal, and you slightly debuff the target. I six slot this. 1 Acc, 2 Heal, 2 Recharge Reduction, and 1 End Reduction.
LEVEL 2 POWER CHOICE:
Dark Miasma: Tar Patch. Great power. +Slow, -Fly, -Jump, -Res. That -RES is a HUGE boost in long fights. I five slot this. 3 Recharge Reduction, 1 Endurance Reduction, and 1 Slow.
LEVEL 4 POWER CHOICE:
Dark Miasma: Darkest Night. This is also a big help in the big boss battles. -DMG and -ACC. Its a toggle, and so my five slots here go: 3 End Reduction and 2 To Hit Debuffs.
LEVEL 6 POWER CHOICES:
Robotics: Equip Robot. In a game of mandatory powers, this is high on the list. No need to slot it much, it stands on its own. I slot with an End Red and a Recharge.
LEVEL 8 POWER CHOICE:
Fitness: Hurdle. Or Swift. Whatever. You are going to be running some toggles, though, so Stamina is still on the list, ED or no.
LEVEL 10 POWER CHOICE:
Leadership: Assault. And here it begins. Three slot with End Red, and love the 11% boost to damage it gives. Coupled with the boost from Supremacy, this is a 36% boost - better than an SO, and with none of that nasty ED business to bring it down.
LEVEL 12 POWER CHOICE:
Robotics: Protector Bots. Since you already have Equip Robot, you can seem them shine right from the get go. Their bubbles offer DEF to all types, and they will bubble all friendly henchmen and you. They will repair all friendly robot henchmen, and they have attacks too. Six slot these puppies: 1 Accuracy, 2 Damage and 3 Defense Buffs.
LEVEL 14 POWER CHOICE:
Leaping: Combat Jumping. I hear a lot of MMs will be taking Teleport. Thats all well and fine; insert the lead in to the travel power of your choice. I picked this because I love Super Jump, and because the ability to get out of an immob is useful to me. I slot for End Red.
LEVEL 16 POWER CHOICE:
Leaping: Super Jump. Its not fun waiting an extra two levels for the travel power, but Assault was just too good to pass up.
LEVEL 18 POWER CHOICE:
Dark Miasma: Shadow Fall. Lets face it, as a Mastermind we are the squishiest of the squishy. A little stealth never hurt, ESPECIALLY if you plan on doing some PvP. The DEF and RES are minimal at best, but every little bit helps. I three slot this for End Red.
LEVEL 20 POWER CHOICE:
Fitness: Health. Or Swift. Or Hurdle. Whatever. You know what the goal here is, and you know how to get to it.
LEVEL 22 POWER CHOICE:
Fitness: Stamina. We are running some heavy toggles, and respawning and upgrading bots in mid battle can be end intensive. Per ED dogma, this gets just three slots.
LEVEL 24 POWER CHOICE:
Leadership: Tactics. You might skip this power, and slot Acc in your bots instead. But remember that most of your bots are going to spawn at a lower level than you. If you are fighting +2, they are +3 or +4 to your bots. This gets six slots: 3 Endurance Reduction, and 3 To Hit Buffs. This combined with Supremacy should be enough to make your bots hit.
LEVEL 26 POWER CHOICE:
Robotics: Assault Bot. What else? This gets just four slots. 1 Accuracy and 3 Damage.
LEVEL 28 POWER CHOICE:
Dark Miasma: Howling Twilight. This is only useful for teams. If you are a pure solo machine, don't bother with it. Pick Fearsome Stare or Petrifying Gaze instead. But nothing is better on a team than being able to rez 5 people at once. I three slot for recharge.
LEVEL 30 POWER CHOICE:
Robotics: Repair. I waited awhile for this for two reasons. 1) You have protector bots. 2) You have Twilight Grasp. But your Assault Bot has a lot more HP, and you are not going to want him to be out of battle at all. I three slot for recharge.
LEVEL 32 POWER CHOICE:
Robotics: Upgrade Robot. Nothing needs to be said here. The recharge on this is a little longer, so I slot 3 Recharge Reductions.
LEVEL 35 POWER CHOICE:
Teleportation: Recall Friend. To be honest, I couldn't think of anything else to take. And it WILL be helpful when your bots get stuck on some doodad sticking out of the wall. This gets one Endurace Reduction enhancement.
LEVEL 38 POWER CHOICE:
Dark Miasma: Dark Servant. I imagine after 37 levels of obedient pets, the Dark Servant will seem obtuse, but it can do helpful things. Besides, who would pass up another pet? I six slot. You can focus on one specific area, or you can go wild. Useful enhancements include Heal, Hold, Immob, To Hit Debuff, Recharge and Taunt. I'm thinking of doing one of each.
Finally, I have found
Khaiba's Mastermind Numeric Keypad Pet Controls to be invaluable in my quest for world domination. And Acaos greatly helped me vet some of the typos and other errors.