I played him in the Beta, I'll share some thoughts.
Blood Puddle is an excellent move that will trade very well, I'm curious to see how it works against some of our standing zoners here. Though it seemed to be able to punish jump ins, dealing with zoning that came from the air was difficult.(in the Beta we had Supergirl, Superman and Blue Beetle who's air projectiles made it tough.) Depending on how well blood puddle works matchups like Deadshot might not be that bad from a zoning perspective, by virtue of being able to trade with BP against standing zoning.
Meter seemed very important for Atrocitus as he needs it to get damage off of Blood Puddle when trait isn't out.
That said, you didn't always need meter to convert of Blood Puddle. IIRC stuff like 22~Puddle would combo, you could do d1~punchwalk after a puddle up close(it seemed weirdly distance dependent), and in the corner you'd more easily combo off it without meter.
Up rage breath was a nice anti air that could work as anti crossup and you could combo off of it in the corner.
F12 was my go to for air conversions and seemed like a decent anti air. It also was great for Dex Starr ball pressure. F123 was slightly plus on block and you could option select f123~punchwalk. If you input punch walk after the string it will come out on hit but not on block. F123 does have a gap before the three though.
In the beta, Batman had to hold pressure from rage breath on block unlike other characters. It will be interesting to see if this is a MU dependent thing or if they cleaned it up.
Without trait or meter, he may be forced to to play a more defensive style unless you want to go hard with his 50/50 string, in which you can be punished tough for blood puddle.
His real dirt comes from his trait in Dex-Starr. Dex-Starr gives Atrocitus nasty pressure, access to some strings that I believe launch for corner combos and are plus, the ability to convert off of a ton of different things without meter and gives him(albeit temporary) solid zoning and a great counterzoning tool in the shield. The shield is also a great anti air.
Chucking out f12 on block followed up by differing speeds of energy balls made for great pressure, and the instant activating shield could let you be cheeky. It usually led to free throws and lots of meter gain.
Any where you could do a EX blood puddle, you could do a Dex-Starr energy ball for that extra juggle, so having Dex out will grant meterless combos out of whatever and possibly much more damage. F123 becomes a hit confirmable launcher, punch walk becomes hit confirmable into corner combos or a little extra damage using either ball or shield.
He also had that blood absorb thing which grants access to a sort of AOE explosive launcher, that could be really good if people can find a good way to get it out.
His Super is very good anti air.
Ultimately I think how good he's going to be will be dependent on how sick Atrocitus players can make him during his trait, but they'll also have to be creative to open people up with out trait in ways that don't involve just yoloing with his 50/50.
