cecilia

Cecilia is the only green mage cavalier that is not a 5* exclusive. I say she can be worth it. Might not be the best, but your chances of max merging her is probably higher than you pulling a 5* exclusive green mage cavalier.

She can get about 80 green magic damage on initiation with a blade tome. Does it sound like something you would be interested in?

Yes. She's carried me since the start of the game. She was my very first 5* promotion.

GronBlade+ does wonders. I have given her other skills for other sets like TA / Blue Tome Breaker / BowBreaker. So she has worked very well for me. I still use her a lot on my main horse emblem team or sub horse teams as a great blue/green counter.

Do you have groom Marth?

Cecilia is good. Nowadays though I mostly use her as a b!Lyn & Reinhardt check with gronnraven, TA3, bow breaker, and cavalry buffs.