| Paige Kuplinski |
Lantern king feels more like a gotcha than the Nyrissa unless you think they will have fun with the chaos. At least Nyrissa has a viable path for redemption. My PC also doesn't want to know who their patron just that he wants their goals to align with the party.
I figure Count Ranalc would have reason in being invested having the kingdom succeed so that Nyrissa is drawn out. If he knows about Briar then he can serve as a greater impetus to search for that and restore Nyrissa's love.
Another option is Magdh. Although her edicts and anathema are more about deals and divination she does preside over a section of a first world forest. She also could easily be adapted into an "witch of the woods" type flavor wise. Plus her ideals suit the pact based nature of the witch class.
All that being said if you want you could probably easily make up a new eldest for your game to use if the options don't suit.