hmm what I think arcanist is like XI's nintsu using tools to make it become magic.

well "in my dream" I think I saw the beastmen summon evil god, so we summon something to fight it... but you know it's just me dreaming... /look around + /whistle
So, ya maybe we summon probably siren, alexander, and carby. I also think it's possible the skill itself is like some ff tactic one summon something pop the skill then disappear.