Having killed myself numerous times on a Riftblade without them actually hitting me at all, I took a look at the damage taken from Avatar of the Rift.

Avatar of the Rift: blah blah blah and causes any melee attacker to take __ air damage.

So of course normal melee attacks such as melee abilities and auto attacks would cause the damage shield to hit back. However, I saw the 54 damage stream from this ability fly across my screen faster than I could ever hit for and found out why! Bleed ticks from puncture, jagged strike, and impale also proc the damage shield as well as bleed ticks from serrated blades, and even poison procs! Now if this isn't a bug, I think serrated blade crits should proc more serrated blades since they're thought to be melee attacks from the attacker.

Just another reason to never attempt to kill a warrior as a melee rogue, and to make sure you're at 80%+ health before thinking about trying to peel them. yay