He had to tap into the Heroic Energies like his Father before him.
Exactly, had had no training of any kind.
Then again, Hammer, Reaver, and Garth are just normal Heroes. There Bloodline does not flow like our Heroes. Our Heroes of the games have THE Bloodline, not any other can have it except blood relatives, To my knowledge, we're not related to a fat bitch, gay gunslinger or a black guy. I do believe these three just held the most skill in the world of Albion at the time Theresa needed them. If say, Reaver was dead a long time ago before Fable II, then I think 'fate' would have chosen the next best person with Skill. It isn't in their bloodline to unlock powers as we can, and they cannot train as efficiently in all three Hero Areas.