Play as Inferno.

2Roty:
1) The point of building a Stronghold in the first week is unclear. We'll spend 5000. This gives us 4 dogs and 8 extra demons. What do they accomplish? Wouldn't it be easier to build Pit Fiends or at least some horses? Buy a tent, and you don't actually need any dogs.
2) Maybe it's still worth taking magic? Depending on what's in the guild—Dispersion or Vampirism—take Darkness, and then no neutrals or upgraders will be a threat. If there's Fire Bolt, take Chaos plus Lord of Fire, and maybe even Firestorm—the finale won't seem easy for your opponent.
3) Overall, it seems doubtful that you can just wipe everyone out with a single Stone Skin and Haste. +9 defense and +30% initiative aren't that impressive; other factions that have Expert Light and similar spells cast them more effectively. And there are plenty of other racers good at clearing territory besides Grok—I don't think he's the best.