I'll assume you are canonblind, (most people are) Garviel's gene-sire (dad more or less its complicated) betrayed him and his grandfather and tried his very best to kill Garviel by turning his brothers against him, collapsing a cathedral on him, and then dropping an orbital strike atop that.

It failed.

So yeah.... daddy issues.

He tends to be rather fatherly towards kids, and previously was even working in a day-care at his last game, so her childish appearance will naturally make him act kindly towards her.

Oh and he's about as big as Bahsaka. :3