I have a question regarding an Ally Card: The Sir William Brenton card from Unseen Forces states "Place 1 Sanity Token on the card" every time you need to use it for a dice reroll, similar to the Clue Token usage Do the Sanity Tokens come from that characters' sanity total, or from the token pool? Thanks.

They're just counters. I wish FFG didn't specify "sanity" tokens. Any counter will do: I tend to use doom tokens because they're smaller.