[quote=@Nanashi Ninanai]
One of the hottest grandma around, still.

Jason didn't deserve her.
[/quote]

Jason, like pretty much all Greek heroes, was an asshole that got famous because their society (like pretty much all other ancient ones) is highly sexist.

Otherwise, why would pretty much all female Heroic Spirits be considered Evil by the Grail in a way or another?

EDIT: Himiko and Tamamo shall be another good interaction as well. After all, it's not everyday that you get to meet a fragment of the Goddess you worship. Having your mental image of her as a regal and proper entity destroyed is just a plus.