Arctic comes from arktos, which is, well, bears. Bear Circle. Bears north, penguins south. ant(i)arctic--opposite bears. No bear circle. xD
My one objection there is that Merlin supplied HP that Castoria didn't, so Proto Merlin has THAT weakness for CQs. You get more damage stacked on arts, but you're giving up the ability to restore chip damage.- For CQ, she's as useful as Merlin was to you in CQs. Has better compatibility with Castoria than Merlin, so if you summon Support Castoria + Girlin I doubt you'll have a hard time beating a CQ.