Every contrivance they use to make Firestorm completely useless. Goddammit.
I just can't. I hate what this show's become. I hate the cardboard cutouts the characters have become, I hate how they try to elevate creatively sterile stories with VFX that don't even look good anymore (in fact, they're embarrasing to watch - Who thought the Nazi Hulk was presentable), I hate they don't even have what can even pass for a semblance of "rules" and yet lack any kind of self-awareness to admit how (unintentionally) surrealistic the show's become (unlike, say, Doctor Who), I hate they present everything they do as "drama" yet most episodes seem like filler.
I'm done for the most part. I'll watch the crossovers and perhaps catch it up if the Legion of Doom appears more interesting, but this four episodes are the worst the Arrowverse has to offer, up there with Arrow S4B.