Want Cu but got Nightingale instead :(

Be happy, that's a sick roll

You should wait for another CU rate up as he isnt as rare as other servants when it comes to banners.

Saving is completely dependent on your current comps, servant preference, and banner forecast. If I knew what your team looked like, we might be able to help you out a bit more with this. If you're F2P or P2P, getting 3+ SR servants is still a godsend and is nothing to be disappointed about.

-----Nightingale is not a bad SSR berserker whatsoever and fills in the hard-hitting team support role with ease. She may not outdamage Cu but she supports far better than him and still deal a lot of damage.
-----Rama is a good SR saber who rivals the stats of SSR sabers if fou'd. He outperforms every SR in his class as well (durability/demonic damage beats saber Lancelot's). I'd consider him a great addition to any crit comp.
-----If you don't have a good SR/SSR support already, Edison becomes a very viable support. It's as if he stole 1/5th of Merlin's utility and incorporated those skills into his kit.

Also consider the banners coming up this year including the summer banner, Jalter's banner, & Merlin's banner. I think these limited servants are worth saving up for as a F2P. If you're on the P2P route, it wouldn't hurt rolling for Cu again so as long as you can budget for the upcoming banners.

Our rolls got swapped?! I was looking for Nightingale but I got Cu Alter instead. 😭

Remember that Nightingale is a rather persistent Berserker and typically appears to those who weren’t looking. ._.

Seriously though. Back when the America’s singularity first popped up and Cu firs became available, I rolled hard for him. Lo and behold, no Cu and a single Nightingale.

She’s great, really but I already have Raikou, Vlad III with a decent art team and Heracles so she really gets left unused as they mostly outclass her in terms of raw damage