Deathblade in set 2 is too strong.

I feel like deathblade should be nerfed in the set 2. last game i was going with summoners/mystic combo and in the late game i came against a player who had 2 deathblades. Since deathblade gives the wearer +15 ad when they kill or participate in killing an enemy, both of them got 13+ stacks by just killing the weak summoners creeps that just kept on spawning.