Lissandra's ult damage should be greatly reduced
A utility mage with what is essentially a permaslow with no items and two forms of AoE CC shouldn't be bursting you.
Also the Q through minions does crazy damage in lane but she's supposed to be a utility mage while bursting a single target.
150 / 225 / 300 (+ 70% AP) AoE
150 / 250 / 350 (+ 70% AP) AoE