Does The Sentry fall under this trope? I feel that he might but I do not know much about him other then that he was somehow known even before he was introduced, and that he is now no longer around.

Could Jesse from Burn Notice be this trope? I mean... to quote the definition: "A character is introduced into a show with a lot of fanfare, and almost at once moves up to main character status" check "He/she will often form a close relationship with the existing main characters," check "and may even have a prior history with a main character, even if this has never been mentioned before." Well him and Michael do have a history. However brief. "Sometimes the character is a result of Executive Meddling." Wouldn't know about that though.

"For some reason the character doesn't gel. Maybe the audience takes against him/her," Well me anyways... "maybe the actor over- or underperforms, maybe the writers realize they have no idea what to do with him/her." The character seems pretty pointless and undefined to me. "Whatever it is, the character will end up leaving the show setting, often for a fairly contrived reason (and they probably won't be back, even if logically they should be at certain points)." Well he does leave, doesn't he?

Since I am new here and not really sure about that, I wanted to check with you guys before editing. :)

Isn't this just The Scrappy or Shilling The Wesley?