Bigbaby
he has Two paths 1.he should gain control over the remaining earth-singers,The three eyed Raven, The Giants and Any race north the wall, plus see if he can control Weirwoods to gain Greensight. 2. Go to OldTown to gain Control of the Hightowers, The Citadel and the Most Devout there as they are the ones controlling who is appointed as high Septon,Gain knowledge and political power. in either way he should try his hardest to train his powers and see if he can evolve himself, as one shadow baby and poof he is gone!