Why does Lackland hate Gareth so much?

NebulousNoxious said in comment #2601305:

Why does Lackland hate Gareth so much?

The pairing is more based on a bit from the Camalot Singularity, where before the heroes arrive the Knights of the Round Table destroyed the Third Crusade, which included Gareth, already doubting what Lancer Artoria had planned, committing suicide by way of sacrificing herself to hold down John Lackland while another knight killed them both. So the story, years before actually including either character as playable, had already had the two interact, and be responsible for each other's deaths. So fans either inflate the hard feelings, or pair them together as here for the irony.

NebulousNoxious said in comment #2601305:

Why does Lackland hate Gareth so much?

He doesn't. She's actually the only Knight that John admired.
Her death in Camelot/Zero is what drove John over the edge and caused his defeat.

Ahhh, I misremembered, I went back and reread. I was mistaken, I thought he had a similar reaction to Gareth that he does Robin Hood. My bad.