He hid his animus powers from everyone at first, but revealed them later in Escaping Peril to save Winter from accidental―but lethal―burns received by Peril. He then lost them in Talons of Power, due to Darkstalker and his animus magic removal spell.

Who broke animus magic?

Turtle claimed Quilbi "broke" animus magic with his soul spells, but even when Turtle took the spell off his magic still wouldn't work.

Why is animus magic gone?

IceWing animus dragons were only permitted to use their power once to benefit the tribe at a gifting ceremony. Prince Arctic's runaway caused the disappearance of animus magic in the tribe, which was bad genetic luck.