I see that the two are compatible... how do people think they'll meld? That gives Gravewalkers... a frankly terrifyingly large pool of controllable undead. Bonethrall, Command Undead, Animate Undead... Yea, nay?
that sound... pretty cool actually lol
It is interesting, but as the Gravewalker gives up Hex at 1st and 4th level, while the Hex Channeler gives up the 2nd level Hex, the character effectively wouldn't have the Hex feature until 6th level (and so no Extra Hex feat). It could be later (10th, since gravewalker loses 8th level Hex too) if they use the 6th level slot to bump up the channel to 2d6. Then again, there's already an archetype that gets rid of hexes altogether, so it's not beyond the pale.
For undead control, though, it is a nice little bump, but other classes could do something similar but different (e.g. Juju Oracle gets 6HD/lvl, Cruoromancer gets 5HD/lvl)