I was making some experiences in Skyrim, and the conclusion is that having tons of mana and reducing mana costs is better than having a good amount mana and mana regen

How things work in LoL? You can't reduce mana costs, and the regens are pretty slow since you are always using mana during fights. Having tons of mana alone doesn't work either. What's the solution?

Damage is the solution. You kill quicker, so you use less mana of your tons. You can't reduce the mana cost, but you can boost your damage. Instead of using skills more times, you can make them harass more