I played my last TDM on Lvl 31 yesterday. I do not have a single mythic item, but high-end legendary gear.
So I met two random wars from the opponent team and fought them like I always do against warris: Charged normal-charge hp-aimed-nox-shadow piercer. And then I noticed I was out of mana after a few seconds (?)...haha. Okay...so I ran to the mana station and refilled it.
To cut a long story short: It seems like to kill one random war takes about 75% of your mana at Level 31.
That has to be fixed as soon as I reach the new level cap.