Okay so spoilers I think.
I chose the sky stone at the choice to choose between the 4 its the first option.
At the ceremony I chose humbling, grateful, Its no longer my home and I walk in their footsteps. Thats what got me sun blessing.
I chose the same options at the ceremony every time but if I chose a different stone it changed my magic so I'm not completely sure but I hope this helps.
Also I think outer or inner magic is also a decider. I chose outer each time.