Different skills can be acquired in the game, usually through levelling up.
There are two main categories of skills - Active Skills and Passive Skills.
Active skills are offensive while Passive Skills are defensive.

These two main categories are divided into four subcategories:

1) Melee(Active)
e.g. Multi Hits - inflicts multiple melee attacks on one or more enemies.

2) Heal(Passive)
e.g. Cure - restores some HP.

3) Shield(Passive)
e.g. Shell - reduces the enemies' damage for a number of rounds.

4) Effect(Active)
e.g. Stun - stuns the enemies so they cannot move for a number of rounds.

Some skill would also have different Levels(usually three Levels in total) which can be improved upon.

All the skills in Melee, and Heal category are done, but I'm still working on Sheild and Effect skills which are more difficult.

I also need to think of some cooler names...