My idea is you could've had Taskmaster as this pesky a-hole who constantly gets in the way, gets defeated, but somehow always escapes. He would've been a recurring thread between movies. And his abilities to copy everyone would've made him a credible threat. Even Spidey should have trouble getting through his style. Like imagine if Boba Fett was a credible threat or Cad Bane from Clone Wars. The MCU equivalent of that.
Then let's say he finally meets Wolverine or Shang Chi. And Taskmaster can't figure out how to copy Wolverine when he goes into a berserker rage or Wolverine and isn't following like typical predictable movement. OR Shang Chi figures out a way to clear his head and use techniques that Taskmaster can't predict or anticipate.