Shen is a full tank champion that has great sustainability in lane. When scaling into late game after getting items, Shen can be a huge tank which is almost unkillable without your carries. Even if you're behind in lane, just buy a Mejai's Soulstealer and ult frequently to lanes to get stacks for it and late game, your ult will just be a huge shield tanking alot of damage.

+ After getting few items can be a huge tank
+ Flashing after Taunt can turn around a losing team fight.
+ Global ult can save allies
+ No mana
+ Can taunt during gank to force summoners

- Passive laning
- Missing your ultimate is a huge disadvantage