My boner for wind meta prevailed in the end, so Titania.
Mammon wouldn't have been a good upgrade for tower purpose coz weak nuke without d'Art & her debuff is useless against the last boss. So is d'Art. Sooo, yeah. Rip thunder. My grid being as is, I doubt I'm gonna have trouble except the last 2-3 floors.
Now my only problem is that I can't yet play with my new toy coz I wanna save up HEs for Phoenix 2nd, as I only have a 1* copy of the bow. Gonna take a while to level Titania to 80.. twice. 😐