I'll elaborate on the seals, then. He's a "lock, stall and stun" sort of fighter, focused on wearing down his opponents by negating their attacks and then disabling their means of offense and defense. His "signature" technique is writing up an ofuda in the midst of battle, which when placed on an opponent puts a sort of mental lock on one or more of their techniques, depending on his understanding of them. If you're familiar with JJBA, this is similar to Rohan's "Heaven's Door" ability. Or just the Pokemon move "Disable." His stronger spells will literally either bind or seal away an enemy, but those are complex and require a lot of prep work. His most basic spells are attack negations; just one-offs that will defend against a single attack. Once he starts getting really tricky, he can start using his seals in a more abstract manner. Sealing away ideas and memories to reshape a person's mind, or sealing away their limitations to unlock hidden potential. Weird stuff like that. Of course, those require complex rituals and components, and aren't practical to perform outside of battle.
I can see you edging towards the "reject" button seeing that last ability, but it's mostly for plot fiat, and I won't use it unless there is an agreed-upon plot reason to do so. In actual battle, expect him to fight like a "Para-Flincher" in competitive Pokemon.
The Blank Canvas is to let him use abilities outside of his "class," in a way, mostly to round him out against stronger opponents, or for plot reasons as needed.
I can see you edging towards the "reject" button seeing that last ability, but it's mostly for plot fiat, and I won't use it unless there is an agreed-upon plot reason to do so. In actual battle, expect him to fight like a "Para-Flincher" in competitive Pokemon.
The Blank Canvas is to let him use abilities outside of his "class," in a way, mostly to round him out against stronger opponents, or for plot reasons as needed.