Skills
In the original SNES game, Chester had no special skills aside from just using his arrows to hit enemies from across the screen. In all of the remakes, Chester was given actual TP-consuming abilities, though apparently in order to balance this out the programmers weakened some of his later weapons. Here is a list of all of Chester's abilities, as well as the button combination for the GBA if you have the Combo Command equipped. I have also included the romaji for the Japanese names.
One reason why I prefer to use Chester as opposed to another mage in my battle party is because Chester is a melee fighter; he can hold his own against an enemy onslaught, and his animations don't pause the battle and make me lose concentration (with the lone exception of Dragon Slayer, but its damage more than makes up for the inconvenience).
Hell Pyre
Guren
4 TP
Fire
Level 3
D, F + B
Ice Fang
Touga
5 TP
Water
Level 8
D, F + A
Thunder Blitz
Gouten
8 TP
Lightning
Level 16
B, D, F + B
Sonic Bash
Shouha
11 TP
Earth
Level 22
D, B, F + B
Wild Rain
Shinten
11 TP
Level 28
F, D, DF + A
Eagle Shot
Shuuu
12 TP
Wind
Level 34
F, D, DF + B
Gale Shot
Hayate
14 TP
Level 40
B, F, F + A
Giga Fang
Taiga
20 TP
Level 46
D, B, F + A
Dragon Slayer
Toryuu
45 TP
Level 52
D, B, D, F + B