I wish I knew. Ciro Nieli had this great idea in a spotlight video you can see on Youtube that would've had him breaking away from the Foot Clan at some point and trying to find his own way in life. It's a great idea because it would've given depth to a character who had an uneasy alliance with Shredder (like Karai) going into S4 despite his loyalty but they blew that from "Earth's Last Stand" onward. And that's also disappointing when you consider that Tiger Claw not only got worse as a character from that point on but it was a missed opportunity due to the fact that this franchise doesn't have a very good Rogue's Gallery.

Basically, when "End Times" came along, Tiger Claw should've either sacrificed himself in the midst of battle so that the heroes could win or he should've been killed (preferrably by Karai) afterwards.