Is it important who you give each esper to? I just got my first one (Belias) and found out that only 1 person can get an esper and I don't want to mess it up. Is it ok if I give all esper to one person, or split them evenly among my 3 most used char? thanks!
Also, regarding strength, how do the espers rank up to each other? I know Zodiark is the best, and Ultima is the second best I think; but how do the rest of the espers stack up to each other?