A cool idea to have abilities scale would be to have spells use a certain % of your mana pool.  The amount of mana they use determines their strength.  For instance fireball might use 15% of your mana and do 3/4/5 damage per mana point used.  This means with a 1000 mana the level 3 spell would do 750 damage.  At 2000 mana it would do 1500 etc...  The numbers I put were probably too strong but you get the idea.  This would lead spell casters to buy more actually mana items.  Rook's boulder throw could rely on his health and Regulus's snipe could depend on his attack speed/damage.

Tyo already said that abilities, at least many of them, will scale based on your level equipment or something like that.

I thought I was the only one entirely irritated by this.  I was just about to start a thread about how when playing as regulus with the gloves that give a major attack bonus, I can do more damage with normal attack than with his snipe ability.  My solution is:

Regulus Snipe DMG=Base DMG + Snipe DMG

Thjis may seem over powered but the rook is hard to take down in lvl 15+ with snipe.

that is why the numbers are not fixed and open to change