[quote=ERode]
Well...if he's Nasus with 9999 stacks, then isn't he going to die the moment he hits Ier-Briar? XDWith 9999 stacks, the moment he Qs someone with Thornmail, he DIES.
[/quote]

Please. Ier-Briar's armor makes no reference to reflecting physical damage.

And actually no. He'd only take 3333 damage in return, less when armor is factored in, so around 1500 probably. Depending on what happens first, life steal or Thornmail damage, he might even walk out unharmed. While whoever got hit is ded.