Why not Simply Defend?
[Wait…what next strike?!]
I'm a pacifist! Don't tell me…
"Yes, our next strike. We need to expend as much as we can. So far, we have been attacking the weaker scattered sects as subtly as possible. We have no proof, but chances are the other big powers are doing this too." (Anon)
"Yes, we've been pretty successful. So successful that we need to create a new pen soon for the captured. Actually, we could expend the current one. That's the best part about water magic, it's so easy to transform and upgrade." (Fairy)
"The only issue is most of our targets were so poor! As much as I love jewelry, it's useless if we can't get mana cores for our training." (Empress)
"I mean, for mana cores, we could simply raid a disaster zone until we have enough." (Princess)