Board Thread:Game discussion/@comment-71.209.218.188-20130210234438/@comment-3308937-20130210234720

If it has a red blood-drop sort of icon then it's the damage you receive from the passive of his Q.


 * PASSIVE: Thresh's basic attacks deal bonus magic damage on each hit. This value is equal to the total number of souls collected plus a percentage of his attack damage, based on the amount of time since his last attack.