Aquaman: You gotta block low when he stabs his Trident in the ground. Same for Nightwing.
Superman: Don't you have air gun shots because if you jump in the air the laser shouldn't hit. Or you could dash and block as always. Also you have the air version of the Machine Gun to cut him down, unless it doesn't hit full screen, I don't know.
Deathstorke: Dash and block. Duck Quick shot then dash. Block low for low Quick Shot and dash. Machine Gun should always be blocked standing because they might meter burn into Grenade launcher which is an overhead; then dash in and get in that ass.
Anyway the really way to deal with a spammers is block, dash, block, dash.
Zoners lure you in close then do damage *Cough* Guile, Green Lantern, Morrigan *Cough*