Board Thread:General Discussion/@comment-25315804-20161206050558/@comment-24674051-20161206190947

The only problem with Gideon being a Dark one is that The dark ones (at least as we understand them) are based from Holy Grail magic. Nimue became the first dark one by drinking from the Grail, and Merlin (who also had HG magic) used Excalibur (which was crafted from the HG) to bind the Dark One, and that binding has passed from one dark one to the next, including Emma Swan and Killian Jones. So that is a very specific form of Darkness, with at least a few very well established rules.

Now, what we DON'T yet know is whether there is any direct genetic aspect to the DO curse, since there are no known decendants that were born to a Dark One after they had obtained the curse. Gideon may well be the first of that, and as a result there may be some new rules that come into play. But I don't see Gideon being bound by the DO Curse rules, and I also don't see Gideon as an immortal creature because of the Darkness. I think there will be other aspects that might present themselves.