Help designing a high-powered fantasy game

[Belac93]

I'm currently designing a point-buy game, with a simple, 2d6+modifier dice system (2- is crit fail, 6- is fail, 7 is stalemate, 8+ is success, 12+ is crit success). This game is extremely high-powered, to the point where starting characters are things like dragons, or mages on the cusp of lichhood.

Combat runs in 2 ways: for mundane creatures (most creatures), it runs off of a hit point system. For Ascendant creatures (PCs, gods, dragons), it uses an injury system (general injuries are the most commonly used, which act similarly to hit points). Mundane creatures can only hit Ascendant creatures on critical successes.

So, I have a few questions:


Should I have PCs rolling to defend, or NPCs rolling to attack?
What are some examples of good mass-combat rules that I can adapt? I want my PCs to be able to fight large groups and come out on top.
All PCs have curses, that affect how they use their powers (lich must feed their phylactery souls). How freeform/up to the players should I leave these abilities?
Good examples of domain-play rules for characters who decide to rule kingdoms.
And, finally, any general tips for a game of this scale? It's not the first RPG I've ever made, but all the others were barely above commoner levels of power.

[Vitruviansquid]

1. To maximize the pace of play, Attackers should make all the rolls regardless of whether they are PCs or NPCs.

2. If mundane creatures are going to be extremely weak, maybe have a rule that can turn large numbers of mundane creatures into small numbers of groups of mundane creatures. Then you might run a group of mundane creatures like a single Ascendant creature.

3. If you are designing a game by yourself, you might want to go more freeform because you wouldn't want to do the necessary work to write up the crunch for it. However, the best rule of thumb for where you want to spend time writing crunch is to think about how much time and often the activity you're writing for will appear in your game.

4. Can't help you there.

5. Think of a main activity you want the game to be concerned with, and make it really really good.