Kalista's E doesn't turn blue when she's out of mana.
If Kalista has less than 35 mana her E icon is gray as if there are no available targets to use it on rather than blue like she does not have enough mana to cast the spell.
If Kalista has less than 35 mana her E icon is gray as if there are no available targets to use it on rather than blue like she does not have enough mana to cast the spell.