I agree, but in some situations, Shen can be incredibly strong, like split pushing or laning vs nasus. All shen has to do is max his dagger and throw it at nasus the second it gets off cd every time and taunt nasus when he wants to q a siege minion.
I disagree. As a nasus main, I find a few champs hard to stack with. Renekton, riven, lee, and other such very early game offensive bruisers tend to reduce my stacking, IF they know to zone me. Shen hasn't even got that much dmg. You also forget nasus' natural lifesteal. Even if shen would do Q+E, nasus can heal himself rapidly back from a few minions, because shen doesnt tend to do that much dmg, as I said.