Assasin's Mark (Akali Passive)

You channel lethal focus into your strikes. For the spell’s duration, whenever you deal damage to a creature with a spell, your next melee weapon attack against the same target deals an additional 2d6 force damage.

Using Higher-Level Spell Slots. When you cast this spell using a spell slot of 2nd level or higher, the extra force damage increases by 1d6 for each slot level above 2nd.