Your new thread reminded me of this one and I thought of another.
Bellamy Blake in The 100. Great character for the ENTIRE RUN and then you get to the last few episodes... and oh... oh my. I get what they were trying to do but they picked completely the wrong character to do it with - it did not logically work
at all based on every single thing they had established about the character over 7 full seasons. I don't even want to talk about it. Abysmal writing
.