Always? Devil-Tyrant Avatar Shintai is the big one. BRR is the little one: establishes that you have a mutation library,<del>allows</del>forces you to manifest up to eight points while flaring your anima (technically a Desecration effect although it ignores Desecration rules), and at Essence 3+ you can keep your mutations even without a flared anima. Also, if you know Fealty-Acknowledging Audience, you can grant an eight-point package with it as a Desecration.