Henry Legolant

The Black Bulls' hidden member: his magic drains the mana of anyone nearby and reassembles matter — he literally is the squad's base.

Ill from birth, Henry survives by passively draining other people's mana: that is why he never leaves the hideout, which he holds together with Recombination Magic and later turns into a mobile fortress. When the Black Bulls are home he feels well — the only cure he has ever had.