Shen is the eye of twilight aiming to keep a balance between the spiritual and real world in a complete unbiased manner not based on emotion. His kit just doesn’t reflect the lore and his ult takes too much power from his kit
The elephant in the room: In the lore, Shen senses imbalance and clasped his hands together. He teleports to the place of imbalance and kills the people killing spirits. So why does he teleport to one person no matter if there is imbalance or not. Why can’t he just teleport to a place in range of imbalance like a team fight. He could get a weaker shield or his W where he teleports to fulfill the tank part of his kit. He doesn’t have to hope the ally he teleports to doesn’t run as far away as possible. It would still be global and a potential game changer in a team fight if used correctly. Shifting the shield from allies to Shen could allow shifting power to his other abilities
The passive: Shen has a spirit blade that he controls with abilities. He also gets a shield when he casts a spell, but it has a cool down. Hitting enemies with spells lowers the cd. It scales with bonus health. Not a bad passive, but the shield is a bit weak early. But based on the changes below, buffing it might make Shen too good when it comes to trading in lane.
The Q: it’s a very nice ability that can spammed in lane. It does surprisingly good damage even if it doesn’t pass through an enemy. The slow is rather useless because if Shen gets the spirit blade through somebody, chances are, he is where they are trying to escape to. They are running towards him to run away. But when the enemy is running away from you it’s pretty good. Aside from that, the energy cost is a bit high but the ability doesn’t really need a buff
The W: Shen creates an area around his spirit blade that makes you immune to auto attacks when inside for 1.5 seconds. The cd is high, so using it for trades isn’t suggested. It’s better for teamfights and defending an all in. I would suggest making it a larger size, increasing duration, but change the dodge all auto attacks to a physical damage reduce effect.
The cool down could be reduced by Shen taking damage, but that might be a bit too much.
The E: Why does it have damage and why does the damage scale with bonus health? Just remove that. Nerf the base taunt duration to 1 second and add a bonus health scaling on the taunt duration. Around 0.03% bonus health or something like that. Full build the taunt would be around 2-2.5 seconds long. Cool down is also kinda high, but that’s good because Shen has to think about playing safe or going for trades. It doesn’t and shouldn’t give him too much mobility because after all, he is a tank.
Let’s sum it up: Shen isn’t “I push top until I need to shield an ally” anymore. Instead of being picked because he can just keep the hardest carry on the team alive from anywhere on the map, Shen has the ability to sway team fights with his global presence and ability to jump into the middle of a fight and tank.