Action: Seething Frenzy

Your eidolon's fury boils over into a reckless, out-of-control frenzy. While frenzied, your eidolon is affected by boost eidolon and gains temporary Hit Points equal to your level, but it takes a -2 penalty to AC. Your eidolon can't voluntarily end the frenzy or start another frenzy while in the frenzy.

The frenzy lasts for 1 minute, after which it's Fatigued for 1 minute and can't start another frenzy for 1 minute.