Team Deathmatch with abilities enabled sounds kinda weird tbh and would mostly have people play duelists and then it'll be forgotten. Why don't do add modes like
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One in a chamber - As the name literally says, you start with 4 chamber shots and for every kill you get 1 bullet back and if you miss then you'd have to knife with those big knife from escalation to get 1 or 2 bullets back.
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Overwatch like payload mode - A mode which is ability enabled where you push the payload while the other team stops it and goes vice versa
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Sheriff only Deathmatch - Either incorporate chamber sheriff with infinite ammo or you can only buy sheriff and the first to 1000 wins, matches can be joined and left in between and will help people practice their aim and no one will stay to get 1000 kills since its stupid but will also make content
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Ability draft - A gamemode where you can mix up abilities of different agents by choosing from a set pool of agents that are voted on (most 10 different agents) and then you pick abilities. E and Ult ability can only be one per agent while C and Q can be multiple. For example, Jett smokes and omen tp (shrouded steps) can be picked by one.
IMO these will add more replay ability to the game and not create dead gamemodes