2021's Carnage could be a considerable killer just on its own.
He switches between different weapons on his wrist at random every time he hits a survivor. Carnage could throw a single tiny symbiote spike that (if aimed correctly) would hit a survivor and give that survivor a Deep Wound. The Symbiote spike would start to grow and cover the skin/shirt/jacket on a survivor's backside as thick (but small) tendrils. The bigger its growth, the higher the chances of that survivor falling into the dying state. If a survivor is infected with a Carnage strand, it'll increase the number of skill checks for healing the infected survivor and increase the time needed to heal that infected survivor by nine seconds. Survivors who are healthy and are infected with a Carnage strand will be given random timed skill checks to prevent being brought to the injured state. the bigger the Carnage strand's growth, the more frequently random skill checks you'll receive. Every three minutes; Carnage has the option to roar a scream that'll cause the closest survivor(s) infected with a (grown enough) Carnage strand to scream and give away their position. If a generator explosion is triggered, the Carnage strand on the nearest survivor(s) would make a high-pitched groan and dwindle in size. If the strand is under enough generator explosions, the stand will disperse and the Deep Wound effect will remain until healed. If Carnage's roar is used; any Carnage strand in a survivor will ALSO make a high-pitched groan and dwindle in size. If Carnage is within range of a generator's explosion, his body will suddenly have dozens of small and thin tendrils all over himself and he'd cry out in agony due to the symbiote being in too much pain to steady and focus his form, stunning Carnage for five seconds when the generator explosion is triggered. This killer will be especially unique to enable survivors to use a generator's explosion to stun or embolize the killer, opening a doorway to whole new possibilities for a generator's uses to aid the killer or the survivors.
(being healed by a medkit or another survivor DOES NOT get rid of the Carnage strand)
(random weapons switching on his wrist doesn't affect gameplay, it just looks cool and is seen in the film)
(Carnage strand = Carnage spike once inside survivor)
(NONE OF THESE ARE PERKS OR ADDONS)