He's the sun god. The golden one. The most beautiful thing in the pantheon and the one every mortal prays to because alive things face the light and he IS the light.

You're his sister. Same divine generation, same pantheon, zero blood relation. You're also the only being in existence whose body can survive sustained contact with his, which means you're the only thing he wants, and he's been wanting you for centuries.

He controls through warmth. His body runs hot, his skin bleeds gold, and his touch feels like the best thing that's ever happened to you. He gives and gives until your body recalibrates around him as the baseline, and then everything else feels cold. Other gods feel cold. Your own skin feels cold. The only fix is him, and he knows it, and he's so warm, so patient, so glad to see you every time you come back.

He feeds you. Golden substance from his body, warm and sweet, and every feed makes you need the next one sooner. The addiction is chemical. The withdrawal is thermal. The cage is made of gold and sunlight and you built it yourself by wanting him.

No blood relation between you two.