Funny enough the big issue is the same thing they mentioned long ago which is rain of fire. Back when it was a 390 rpm Vex was meta and bungie mentioned the issue was mostly it's synergy with rain of fire. But instead of making it only work in pve or maybe making it so in pvp it needs multiple vex kills they instead nerfed vex itself. Vex rn is just a slightly better 360 rpm auto in pvp. But with rain of fire you get a 30% damage buff every kill + stuff like stability Imo if I'm being honest here this is what they should do. In pve getting a fusion or linear kill or rapid hits with fusions/linears you get radiant, passive 50 AE to fusions and linears, reload when using things like icarus and weavewalk, and getting a kill with a heavy linear grants 4 stacks of surge mods matching your heavy linear. In pvp however 2 rapid kills are needed and cannot be activated with rapid hits. Everything else stays the same even the 4 surges on a heavy linear kill. I'm giving the exotic a decent buff for pve but also making it so in pvp it doesn't give out a free buff for Vex. However I doubt bungie will do this instead most likely "Reduced vex range stat by 10" is my guess.