Things that make games interesting: forcing players to regularly make decisions about their play mid-fight. (example: astral/umbral) Incidentally, they could even improve that further by ripping off the Arcane Mastery system from WoW, where damage is increased the closer you are to max mana. You know what's a real choice? Deciding whether to dump full MP for a Flare with massive burst, or maintaining higher DPS with Fire I spam and a Flare to finish.
You know what's not a real choice? Using Aero I/II/III against Titan just because he's Earth element, changing nothing else about your playstyle for the duration of the encounter.


(p.s. 1000 char limit is so frustrating)