>>530903265
Tsubaki. I'd put them all into her.

Generally the best practice for exchanging elephs for a student is to do it, sincr the chance of pulling a specific 3* is very small and you get 50 ligma for a dupe.

Since she is a 2* you are going to pull her eventually and probably soon, so save them for when that happens the n 4* her immediately and start farming her elephs for 5*

Tsubaki is useful early, mid, and late game and having her overpowered will be a huge help.