Originally Posted by Kiddalee
I don't know much about Shen, but one thing I do know: shields and taunts don't use magic penetration. Do not get Sorcerer's Shoes.
Actually, Taunt now does use magic pen since it does magic damage. Shen does decent sustain magic damage with Q since its on a **** 3 second CD and his passive if you autoattack enough. If you got 1 tank and 1 off tank already, you can go AP/mpen. You'll get tanky too because your shield will soak soo much damage.