CDC is distortion / L3 light which is pretty amazing honestly. Makes great pairing with other melees. After that Req is pretty amazing though it really depends on your target and how many buffs / debuffs you may or may not have. KoTR isn't that bad if you have 99 Excal due to the +40% boost and the mods being things that RDM gets tons of anyway. It would be better if it got a second hit before DW is factored in, many of the relics would do better if they had that. And DB is way after all those, it's really just an underpowered KoTR with a lackluster additional effect.