Bansho said:
How do I add this to the "Ultimate Moe Situation" pool?

or rather, who do I ask to add it?

Or rather, how should I make that particular pool. It hasn't been created yet.

yes it has:
http://danbooru.donmai.us/pool/show/64

Pool search function fails. :(

Anyway, only kristallimeri can do that since he's the creator of the pool.