V: I don't really remember. Only played it once

VI: I don't really remember either. Played twice, but I think i hardly bothered trying to teach Strago it because I think it was annoying to learn. If Gau counts then his was spectacular and very easy to acquire.

VII: Pretty easy to get them as well. I don't think I used them that much though. I just remember Trine being powerful.

VIII: Though tied to a Limit Break they were good because it's easier to trigger them in this game compared to VII and X, just have your character in the yellow or close to the yellow and you can spam the hell out of them. I liked them as items for me. I think there's more than one way to get that Degenerator because I never refined cards. Mighty Guard becomes useless once you get Invincible Moon though.

IX: Somewhere in the middle. I liked having to eat enemies, but like Boko said, sometimes it could get annoying when you accidentally kill them, but I quickly learned how many attacks to use before I attempted to Eat and then you have Cook which isn't a good enough skill for Trance, but it allows you to eat enemies at higher hps, but it becomes pointless once you learn Matra Magic. The spells themselves had weird ranges. I don't ever see the point of using Night or Goblin Punch. I used Frog Drop, Pumpkin Head, Angel Snack (early game), White Wind, Matra Magic, Twister, and Earth Shake most of the time. I think I only use Mighty Guard for the fight against the Earth Guardian and 1000 needles occasionally.

X: They were a joke. You had a couple that were cool like Stone Breath, but I remember not using them for the most part just like Kimahri himself. Nova still isn't as good as everyone else's Overdrives.

X-2: I don't remember much, but I think they were more useful. It was annoying to get some enemies to use them on you and I got game overs trying to get that barrel chested monster to use it on me. I can't remember the name of the spell, but that trout is powerful.