[quote=@Lmpkio]
<Snipped quote by TheWindel>

Fine alright. But I suppose as a character, or rather an NPC character, he's fine right?
[/quote]

Mind that, even as a NPC (if you choose to go this way), you still cannot add him on this battle. Upgrades must gained during intermissions and Zeruel didn't began this battle with the ability to summon him noted on his CS.