In what sense it is fragile LOL?I honestly do not think that Cerys needs a nerf.
To use Cerys you have to run Ursine Ritual as your leader ability or using her becomes very gimmicky.
Having played Lippy decks with Cerys myself I can assure you that the deck is a lot more fragile than you imagine and reusing her in Round 3 is not as trivial as it may sound.
In fact the deck is maybe tier 2-3 at best and due to its nature loses in a long round 3 (which means that losing Round 1 is somewhat of a death sentence), even if one does not brick.
You play Ursine Ritual, you have Cerys, Lippy and you have Royal Decree. Even if you are unlucky, you use Royal Decree to pull the card you need. And if you're lucky, you use it on something else.
I do not exaggerate. Every time I play against this deck I see this combo.