It's pretty much unfamiliarity. I've only fought against a few so I don't really know what he does or how he works. All I know is I got zoned tf out and kept getting trapped. I play a lot of batman so I'll probably start using him more against firestorm when I get the chance (the character I play the most is Joker)
Batman can somewhat zone FS if he has a lifelead, unless FS has trait. And he outpressures FS upclose while getting comparable damage.
FS is mostly a rush down character tbh, to get past his zoning just duck, walk, duck, walk. You'll duck the fireball and block trap as the trap is a low and fireball is a high. He's not going to be chipping you or doing any damage with his own zoning, it's just to build a bit of meter to use for when you inevitably get in.
His buttons for playing neutral are pretty average except for B2, his splat OH. However he only gets 7% off this unless he's on lvl 3 trait. When he is on level 3 trait watch out though cause he can get big damage into a vortex from it.
Up close he gets + frames off MbBurst and 112. After MbBurst, which you'll be seeing more than 112, he's +4 which is plus enough to frame trap into B1(his mid) which he gets a 50/50 from. You can back dash the B1 depending on the character but B12 will blow certain back dashes up.
His mixup options are either B2 and low trap or B12 and B1xxlowtrap. All options are unsafe except for B2 so make sure to get your punishes down.
That's all I've got rn, should cover most of the basics. If you've got any other questions though just ask
