Iono is less good than Kerria but not bad. Still better to use her than a 5*. Evade girls are always worth as long as the enemy don't have precision buff. Crinum is a 5* with intercept for all. Good girl.

50k sounds like a lot but it's so easy to get them. You can even go for more than one to fill your teams. Once again, it's better to use 4 times the same 6* than 5*. And you can replace her after that.