Last Remnant, David/Rush Soulbonding fic or art. I have two angles, either of which I'd love seeing here. The first would be a romance/friendship angle where the soulbonding/Binding is a mutual thing that they both want (seen as an ultimate expression of trust sorta thing).
The other would be a slave based AU, where Rush is a known Remnant and captured/gived to David as something like a coronation gift/first remnant. Soulbond/binding would be very much unwanted on Rush's part. He'd possibly fight against it if he could, your choice.

I haven't seen any fic or art from either of these angles before, so I wait in anticipation! :D