The MC30 title card Admonition lets you:
"...during the Spend Sefense Tokens step, you may discard a Defense token to cancel one attack die."
So can I exhaust a token, gaining its effects, and then discard that token to cancel a die, all during the same attack?
YES!
(it's the whole point of the title)
I just played a game where my opponent said I couldn't use the same token twice during the same defense tokens step. Therefore, after spending an evade token to red, I had to discard another one to get the Admo effect. Who was wrong here?
Your opponent got it wrong.
Because you're not spending it twice.
Your spending it once.
Then you are discarding it.
NOT the same thing.