[Slydria]

2) Is it plausible for a Youkai to shrink in size via summoning them or some other means? i.e. a Kilkenny being summoned with minimal focus, and instead of a big 'ol cat, we get a small kitten-youkai that has minimized power?

3) If yes to the above, would that mean the amount of focus drained is reduced?

2) Sure.
3) Proportionally to the power, sure.

I'd say it would lower the drain, yes.

Alright then, you can consider this approved.