Just a quick question about one of cards from Tristayne Plot deck - Wild Energy.

Let's say I have zero threat tokens and use this card. If attack misses (or doesn't deal any damage) I would just defeat chosen monster and would not suffer second penalty (discarding token), right?

Yeah your interpretation is correct.

Love this card, by the way. Tristayne's Unstable Forces deck is one of the (very) few that I call a decent plot deck.