really just 8 would be enough(with a maximum of choosing 4 of them) but 16 wouldn't be bad, so long as it's just not a few more thrown in there that suck..
Also most of WoWs spells are rehashes of each other and just... it's like a spreadsheet game.
I love some of the skills in guild wars like Bull's Strike.
It's a warrior skill with a 10 second recharge(about medium for a warrior attack skill. They range from 3-15 seconds usually), and 5 energy cost.(warrior gains 6.6 every 10 seconds, but a lot of their skills don't cost any energy). It deals nice +damage and knocks the target down if they're moving when they're hit, and it's melee only. It's on every nearly every Warriors bar.
Knockdowns are powerful(like stuns on DotA) but the skill isn't overpowered because it takes skill to use. The condition on it means it sucks if you suck. If you don't land it on someone moving then it doesn't do anything. You just wasted your energy. And you can't simply spam it every time it's recharged, you have to use it at the right time.
It isn't so simple as using a speed boost and queuing the skill, so once you reach someone you use it. All the good players will stop when they know your bulls charge is recharged so you will use it on you when you're standing still and waste it, then it's recharging and they can run again while you're stuck in place from the attack animation, getting a lead on you again. So you have to position yourself to the side of someone so you can hit it at any time, or catch someone running by you, or have really fast reactions to hit someone right when they start running before they get out of range. There is a lot of positioning to keep yourself close to someone, instead of attacking right at the edge of the max melee range.
But none of that positioning is present in Demigod.. it doesn't matter. And the skills are simple do x damage to target or in x area and stun or don't stun, or do some DoT.