Basically, what P_budy said.
But on top of that, I think a lot of people didn't understand what Volg said exactly. His idea is even better than mine or anyone else's in this thread, because he kills multiple bunnies with one stone.
Many strive to change the landscape of FL via RP plots, "Buildings" and other landscape changing mechanics.
Thulgan destroyed Rheydin. Anamus rebuild it. Kaylia made it possible to follow Lloth.
How about if you could leave behind you, instead of a building, a legendary item, that is closely connected to your RP and can then be used by others? Sepahoona's Third Arm, Jaspurr Lion Pride, Kurvikhel's Soul Stash, Garacci's Thread Dissolver?
Cool items that people will spend their hard earned RP points on. What better way to stay in FL's history that this? The immortals can even work with the players that played a legendary character if needed, in order to create new items with proper abilities and history to reflect the RP of the character.
I like this idea so much.
Also, why shouldn't RP give you PK advantages? RP is something that everyone benefits from, while in PK, it's just you. It makes perfect sense to me, to give PK rewards to those that enrich the atmosphere for everyone.
What I think was bad, was the RP requirements added earlier, because RP shouldn't be forced like that. It should be encouraged, otherwise it won't be quality. But that's a different topic.