Who would stand a chance against Tengu Shredder?
 

Without a doubt, Tengu Shredder was the most impossible villain to defeat throughout the 4kids series. To defeat the Tengu Shredder, the turtles had to get training from the Ninja Tribunal, become dragons, they needed all the help they could get, like from the Justice Force, they even got help from the bad guys like Hun and Bishop. And it took Karai to drain his energy for him to finally go down.

Tengu Shredder is so powerful, he took out the whole Foot Army with one shot in New World Order.

While Tengu Shredder is the most powerful character the turtles ever faced, he wasn't the only impossible one to defeat. If any character from the show would stand a chance against Tengu Shredder, I think it would be:

Lord Simultaneous
Ultimate Drako with the time sceptor
Utrom Shredder from Same As It Never Was in his huge exoskeleton
Baxter's robot from City At War, that thing was pretty unbreakable
The Mystic Ninjas (if they were against him)
The Ninja Tribunal's wooden warriors

What do you think?

The ghost of Yoshi... duh.

Honestly, I don't think that anyone featured in the show could've really stood a chance against the Tengu Shredder.