It's a modified version of the "auto-pilot" combo. Kinda hard to get down, been working on it for a good two weeks and still can't get it consistent enough to make it go-to. But decent progress has been made.
Notation is:
Tri-jump j.M, cr. L, cr. M, S, j.H, fly, j.M, j.d+h, unfly, addf j.d+H, cr.M, S, j.M, j.M, j.H, j.d+H, S(, OTG, PC/Iron Avenger)
Pretty sure I got that right. IM's one of the harder characters to maximize damage with. He has good easy stuff (Guide combo one is very easy, 600k is decent payoff for it), but pushing him to 700k territory without an assist is sometimes a pain in the ass.
In the meantime, I've been using an otg assist and just doing two reps of guide combo one to make it easier