1 - Don't let him position his sword behind you. If he manages to do it once with a taunt or smart placement, don't let him do it again.
2 - Wait out his W or attack him with abilities during this time. It only blocks autoattacks, meaning Shen is still vulnerable to abilities during this brief period.
3 - Dodge his taunt. If you get hit by it, try and turn the fight or disengage since it has a very long cooldown early.
4 - If his ult is up, ping your team to be careful. Try to stop him with a displacement or CC if he ults within your vision.
5 - If he manages to get an ult off and you can't follow up with a TP or roam, shove his tower. The bonus gold from tower plating makes early ults not worth it for Shen.
6- He has no ranged abilities. Poke him and bully him in general. Shove him under tower so he misses CS.
7 - His primary damage type is magic damage, buy early magic resist.
8 - Play one of his counters such as Yorick or Riven.
9 - Have your jungler gank him after he uses his taunt as he has no other escape.
10 - If all else fails, ban him.
Also, obligatory note: Shen has been super weak and repped one of the lowest winrates for the longest time. He has counterplay and he's definitely not too strong, **if anything he needs buffs. **