[ Reiner considers for a moment, eyes idly looking Hijikata over like he might spot some sort of inspiration. He guesses Hijikata already has things like 'keeping weapons sharp' taken care of. Indeed, the best thing to focus on might be more basic things. ]

… How about something that makes you feel refreshed, like you just had a great night's sleep? Or something that improves your balance, or temporarily hides your scent?