Hey all!
I’m new to the forums but a long time lurker so I finally decided to register 
A little backstory: I love Iron Man (IM) and how he plays. I’ve been playing him since vanilla but my interest in him grew in Ultimate seeing as how the changes actually made him more appealing for me to use. Currently, I have two teams with IM, one where he’s on point and the other one where he’s on the second spot with Repulsor Blast (RB) assist and Zero on point (sounds cheap already, right?!) but I will only be discussing the former since this is the one I have more experience with. Anyway, I hope you enjoy the read!
Iron Man α /Sentinel γ/ Doom β.
I feel IM’s main weakness is how he is unable to force an issue on his own. He can zone okay but if you’re missing your Unibeams, the enemy is going to get in your face fast and doing various RBs on their own is only delaying the inevitable; sure you can vary the timings on when you do Repulsor Spread but all it takes is one correct guess by your opponent and IM gets comboed. Plus, his rushdown without the right assists is just lackluster.
Doom helps IM immensely (and any character really :P) with the missiles and since IM can cover his assist calls really well with RB, you can basically be sure that Doom will always get in and out safely as long as IM gets the RB off. Once the missiles are in play, the enemy has to play passively until they’re gone which lets IM focus on one of two things: either on rushdown or on zoning and this decision usually is based on the distance of the opponent relative to IM and if if he/she is blocking the missiles. People usually jump back when missiles are out to avoid having to block them so I just take this chance to get a couple of Unibeams in and, as an added plus, I get more breathing room to call Doom again and get RB off to cover him.
The other scenario is one where the opponent ends up blocking the missiles. In this situation, depending on how close the other character is to IM, I either go for chip if the opponent is far away or go for a up/down mixup if the other character is right next to me or if I can close the gap quickly enough. The mixup is the one where IM jumps straight up and dashes down with either a j.L for an overhead or lands and goes low. This mixup is very hard to block so I like to go for it whenever the opponent gets pinned by missiles. Basically, IM’s goal is to use Doom missiles to force an issue where the opponent gets either chipped if he runs away from missiles (allowing you to call Doom again and cover with RB) or has a 50/50 chance of getting opened up if he doesn’t.
As to why I use Rocket Punch assist instead of drones: I used it to extend IM’s combos, getting in another RB after flying screen. If the combo ends in a corner, it’s a Touch of Death (ToD) since the THC into Plasma Storm is usually more than enough; if the combo ends midscreen, you can THC early into Plasma Storm or late into Hyper Sentinel Force but sadly, it’s not a ToD. Realistically, I don’t need drones since Doom missiles is the only assist IM really needs to win (at least with this team anyway). The second spot can be anyone who synergizes well with Doom and can extend IM’s combos. Sure, Wesker is a prime pick but Sentinel and Doom are great together… and I just love my giant robot <3
Well that’s the end of that! Feel free to comment, the opinion of another IM player is always an opinion worth taking note!
Cheers~