I picked Sel, Ruin, and Third Ideal Radiant
I went with Sel because it is the planet with arguably the least conflicts(or least important).
Ruin and preservation merged, so I wouldn’t really have an enemy. I feel like that’s an obvious choice there.
The Third Ideal Radiant is a lot more powerful than a mistborn, as Radiants are more Invested. Also, having a Spren as a buddy would seem very nice