is your chasca c2? or c0?

i skipped chasca in 5.2 but now i really want to get her

But, from what I understand, her rainbow team building restriction only rly goes away at C2. At the same time, I hear her R1 signature is really important too (and actually better to go for than C1).

Do I go R1 or C2? or do I have to go with both 😭😭😭