Small tip for you also.
Most of the espers in the game provide a stat boost which permanently increases the stat they boost when you level up when you have said Esper equipped makes for fun customisation.
Its a little bit like thestat system in FFIX where your stats increase permanently depending on the equipment you have at the time of leveling.
This is what GamePro would call a "Hot ProTip."
Yes, this is the metagame of FF6. Unlike 7, there aren't items that will raise your stats, but Espers will, if you have them equipped on level up. It doesn't matter what magic you know from the Esper, just that you do have it equipped.
I have often heard of people monitoring their EXP for when they'll level up next, and then switching to an Esper with the stat bonus they want, leveling up, and then re-equipping an Esper that they want the character to learn magic for...
But, I myself have always been far too lazy to do that and just equipped Espers to folks with a Stat I wanted continuously boosted for a character, and hammered my way through the game like it was a Green Pepper And Sausage Pizza.*
What can I say, I like having the battle speed at 1, it's *exciting*
*That said, stats all max at 128. Any values over that will not have an additional benefit.**
**except raw attack and defense power but those can only be boosted by changing to stronger equipment and this is getting too long omg ._.