Raid Mode is a BepInEx mod that allows you to play together with all your friends! It also scales up the difficulty automatically as people join and fixes many multiplayer bugs.
Raises the limit on how many players can be in a game together to 20.
Linearly expands the vanilla co-op difficulty scaling as more players join the game.
Reduces the animation slowdown effect for enemies when they're hit, based on the number of extra players.
Adds an additional max stamina burn penalty for being revived when there's extra players in the game.
Makes inns more usable for large groups of players by increasing the limit on how far apart players can rest together.
Fixes many annoying bugs that would occur when there were extra players in a game.
Allows the host of a game to use split-screen in multiplayer. But they must have started the split-screen session before opening their game up to other online players.
Best of luck adventuring! If you encounter any bugs, please report them on the mod's Nexus page linked above and list any other mods you may have.