There are 5 types of abilities: Offensive, defensive, movement, buff and omni.
Offensive: Abilities that attack your opponent (fireball, thousand spears attack, poisonous rain, any combo etc...)
Defensive: Abilities that you use to defend yourself from direct attacks (shield, armor, mud wall, wind barrier etc...)
Movement: Abilities that help you move faster than normal or help you cover distances quickly (dash, teleportation, portal opening, wings etc...)
Buff: Abilities that buff other abilities (move faster, offensive abilities can't miss, see further etc...)
Omni: Abilities that block and attack at the same time and do other stuff too (tracking abilities, wall that blocks then reflect attacks, tornado that protects then shifts into a spear etc...)

Level 1 (7 abilities): 3 offensive required, 1 defensive required. 3 free choices. No omni allowed.

Level 2 (10 abilities): 3 free choices. No omni allowed.

Level 3 (13 abilities): 1 omni required.

Level 4: (16 abilities): 2 omni required.

From level 5 to 10, you decide which abilities type that you want to create!

When it says "required", you can have more than the given number, but you need to have that amount at least. If it says 3 offensive required, you can have 4 or 5 offensive abilities, as long as you have AT LEAST 3.