Why I think Shen can't really be balanced
Riot shoehorned Shen into two different classes at once which will only continue to become a bigger problem down the road.
Originally he was just a "meatshield" (like Braum) that just kind of absorbed damage and protected his carries. His old Q and W and Passive didn't help him do that but it did help him be a top laner which was good because all Shen wanted to do was protect ppl (and top lane was a safe place to farm to that point)
So basically, he was an efficient meatshield who only really needed E and R to do his job.
Then all of a sudden, Riot slaps on half of a duelist's kit on his previously useless abilities. Now he can be pretty good at dueling in addition to being the protector guy.
As much as I would love a dueling Shogun (Warlord Shen), I think the majority of Shen's dedicated playerbase would prefer if he was more geared towards protecting others over dueling enemies.
His reworked W could potentially be a really cool "protector" spell, but due to it's super short duration it's way better used as a dueling spell similar to Jax' counterstrike.
But I think the Mortal Kombat Kenshi psychic sword mechanic should be scrapped and be reused in a later champion (Duelist Shogun??? :DD). I know Riot has already said they feel like Shen's rework "didn't hit the mark" which is why I'm trying to throw some ideas out and see what others think.