??????/Poison

I want too try poison. Will Ninja/Poison be ok or what other primary?

Hmm, I never played a Ninja's yet so i can't comment on that.

Poison is nice. Works best with a set that has at least one melee pet, Necro, Demons, Thugs. Necro for Living to stack the -ToHit, Demons for Killing for -Res, Thugs for AoE Dmg.

You may or may not like poison, it's a hard set to learn to use due to its Click Debuffs(seems some like to toggle and forget). You will die on a poison since you get no self heal in the Poison.
The debuffs are early and the slow is a nice way to open up on some mobs(for others the -ToHit one). Since the Debuffs are clicks the Rech are (if i recall) 8Secs(-Def) and 16Secs(-ToHit). Poison has basically evey Debuff type. -Heal -Regen -ToHit -Acc -End -Reco -Res -Def -Dmg. That all i can recall atm.

I enjoy the Rez for a fallen ally(Mega Buff with a funny side effect of a 4sec hold of 1000Mag)
I skip the clear mind copy on most builds due to fact you want to be debuffing more then buffing on this set.
The heal is weak and slow still. The Clear Mind Copy plus the Heal gives i think 30% Res to Toxic in total.

The T9 Gas is powerful depending the the pet T# The T1s are about 75% on the Debuff the T2 are the normal 100% while the T3 is 125%.

I hope this tid bit of Poison info helps you in anyway. It toke me about a month to solo my Poison(wanted to see how long) form 1-50 fully solo no teams no TFs and on 0/1. I had fun with it and that was before the Buffs(AoE Splash).

The best combo, hands down (IMHO) is:

Thugs/Poison... mostly because the Bruiser makes the perfect melee pet to cast the AoE debuff on.

I played a Necro/Poison for quite a while. In fact it was my first villain. Which was long before the set got buffed. Back then it was strictly single target. I wouldn't reccomend a Necro/Poison or Ninja/Poison for someone starting out with MM's. Ninjas are very squishy and they benefit from sets that add to their defense or have very strong AoE -to hit debuffs.

While I haven't played these sets it seems like they would be good:

Bots/Poison and Demons/Poison

With poison you want pets that can buff themselves (and you).

Nin/pois was my first attempt at an mm (and first to 40, before the cap went up). It is the twitchiest, micro-manage-y-ist combination I have ever played. I didn't (and won't) bother to take it to 50.

If you really want to play poison, I would suggest pairing it with bots, thugs or demons. It's much better than it used to be, but still a secondary that requires more micro than I generally feel like doing these days.

I suppose, if your happy just playing at +1-4/x0 then nin/pois might be more fun, but I like going up to x2-x6.

Ninjas are among the squishiest of pets, and /poison is likely not enough to keep them alive consistently. As a MM, you pretty much have two ways to survive an encounter:

1. Be the tank for your pets - /poison is a terrible option for being the tank; no self-heal, no status protection, no defensive powers.

2. Let your pets tank for you - /poison is a decent (though often overrated) debuffing set, but not enough to keep them alive reliably.

As for what works well, Thugs/ is popular, though I'm a bit biased as one of my few 50s is Thugs/Poison. As RiverOcean mentioned, the bruiser is the ideal candidate for noxious gas as he prefers to be in the fray for most of his powers, and the defense from enforcers is solid (be sure to slot defense for them). I suspect demons, bots, and necro would all work relatively well as they all have enough mitigation of varying flavors to stack with the debuffs of poison. Ninja and mercs would be my last choice to pair with it.

Personally, I'd be inclined to tell you that if you want to go /Poison, to take advantage of the fact that it's been Proliferated and make a Fire/Poison Controller.

If you're set on a Mastermind? Eh... Necromancy maybe.

I24 Proc Chance = (Enhanced Recharge + Activation Time) * (Current PPM * 1.25) / 60*(1 + .75*(.15*Radius - 0.011*Radius*(360-Arc)/30))
Single Target Radius = 0. AoE Non-Cone Arc = 360.