This is by no means my idea and taken from a mmo but i would love to see this implemented.

Basicaly a relic weapon is ment to be the ultimate weapon in its class you start off with a weapon that is say lvl 1 and has a speed of 99.9 with no stats what ever, this you have to farm for and should be untradable. Once you get tour weapon you take it to a npc in the town and trade it to him he will give you some gumph about how it is a weapon from ancient times and used to be umbelivably powerful but the energy has faded. Now he says that he can fix the weapon but he will need some things to reapair it.

example of how this works

crossbow of dispair
lvl 1 speed 99.9
You trade 1 low lvl pink crossbow+crossbow of dispair plus 1 million gold and have to wait 1 day
you get back
Dispair Bringer
lvl 10 req 20 dex speed 20.9
You trade Despair Bringer + 1 low lvl pink auto crossbow plus 3 million gold and have to wait 3 days
you get back
Harbinger of Dispair
lvl20 req 40 dex speed 2.0 5 dex, 3h/s, 3/ms, 3% crit, 5% Dodge
You trade Harbinger of Dispair+1 Swamp pink bow plus 10 million gold and have to wait one weekyou get back
Gandiva (This should have a completely dif skin to anything in the game you worked hard for it you want ppl to see you have it)
LvL 35 112 dex speed 0.5 10 dex, 6 h/s, 6m/s 10% crit, 5% dodge attacks will occ cause Nature strke (this is a combo if you didnt already know)

The idea is you have to work for these weapons and they would need to be scaled up with expansions the ones in the game I used to play I never managed to get the final upgrade but was close to it and it took me 2 years to get to that. I dont expect this to take aslong but would like to see a weapon that I have to work for and is extreamly rare in game these should be untradable aswell.