Bramble vest and questions....

I can understand how the Bramble vest would do damage to a person in combat with them wearer. But my real question is "Does it actually make sense if the opponent is NOT a melee type fighter ? Such as Twitch, or Ash or any ranged spellcaster ? " I was using both karma and Soraka trying to beat Nasus in the training tool and both time after a long battle It cae down to being unable to beat Nasus. It could be my build is off but heck casting spells and taking damage from that vest sees a bit much to me. How do You others feel about the vest ?