Nimue is the 2019 Show Exclusive for Hellboy: The Board Game. Normally only available at events attended by Mantic, she is available for a limited time only (and while stocks last) on the website.

Errarta: 

Mangle with Magic

The "Otherwise" text should read:

"The visible Agent who has suffered the least damage (use Target Priority if necessary) suffers 4 damage, ignoring Defence. They can spend up to two action cubes; each one reduces the damage suffered by 2. If there are no visible Agents, discard this card and draw another."