Esiralla is Neowise's """evil""" clone, created by the queen of the multiverse Serenus shortly after he was born. He's been raised by her his entire life, with the sole purpose of killing his other half. However, unfortunately for him, any hurt he does to Neowise, he feels. And if Neowise were to die, he'd die alongside him. Esiralla also works as an assassin for Serenus, killing anyone who she considers 'dangerous'. He often puts on an aggressive front and can be ruthless in nature- but that's just because he doesn't usually have a choice but to be that way. Once you get to know him, he's very awkward and kind of pathetic, albeit a bit edgy... though he didn't earn his fearsome reputation from nothing, either.
He has all the same abilities as Neowise does, and though he's physically weaker than him, he has much more experience. He's able to disguise himself near flawlessly... if it wasn't for the fact that he can't stop parts of himself from appearing red (which is why the shine in his eye is like that). It's the result of an accidentally permanent body modification he did to himself.