Should i level up altera

Every ssr is worth to raised
Beside that, if you doesn't have AoE Saber yet.. Raise her

Yeah, she's worth it. Altera is one of the best buster crit sabers out there. She's a selfish servant which is why she isn't top tier but with on-demand stars and an increased star gather rate skill, she is such an amazing servant. Not to mention having the most powerful AoE NP of any saber in the game to date.

I also have both and admittedly I use Lancelot more often because he is more fun to play.
Altera, however, is always super strong - even without crit stars -because of her skills and high base stats. So she is easy and effective to use. Do it! ;)