idk if this has been posted or not but Izaya support works like this:
His 5S is a counter, he doesn't stay out for that long but it's still a decent amount of time, if the opponent hits Izaya they will get counter by said counter follow up that launches the opponent in the air(not that high) and can be combo ed off. If you support cancel into 5S on hit he will do the counters follow up and on block he will be in counter state.
6S is a grab that looks like a low but it isn't, Izaya jump on the opponent which will be downed if the grab hits, if you use your Trump Card during said grab he will kick the opponent to you so you can continue/combo off it, if you use a CA he will kick the opponent to you so the CA will connect.
This is what I've found out so far about Izaya.