Toxic Strike's description is obscure :  The rogue aims for a vital area, Weakening the target. (Toxic Strike) - Also causes a Corrode damage over time effect that builds in potency the longer it remains active. That mean the DoT cause another Tick that is builded in fonction to the previous Tick (caused by the DoT), more clearly :  There was 8 Ticks before I took the screenshot, after the initial hit: Toxic Strike hit > 4/9 > 4/13 >4/17 > 4/21 >