A tech/magic modpack to enhance vanilla multiplayer experience with mods like Create that allows you to build complicated machines to automatize repetitive tasks alongside Immersive Engineering mod, that gives you a more immersive experience than other tech mods.
But if you prefer a more RPG/Mystic playthrough there are mods like Ars Nouveau, Vampirism and Mahou Tsukai, that adds many well made spells and features.
And of course there are many other quality of life mods to make things easier.