I dont understand...its a level or a map or a game mode or just characters ? have they licensed the name ?
Its a 4 vs 1 game. One killer chasing 4 survivors. They release a new killer after every 3 months and sometimes survivor too with the new killer.
This time they are bringing this "Pyramid Head" as the killer from Silent Hill and survivor from same franchise as well. Every killer in the game has unique power and perks. As for survivors they come with the unique perks only, but any killer or survivor can learn and use any perks.
Sometimes they design their own original characters and sometimes they get characters from other franchises, like Stranger things, Halloween etc
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Survivor is basically just a skin but every new survivor comes with 3 new perks. So you can teach those perks to other survivors (or "skins"). But every killer is unique because of their abilities and power.