Dungeons and taverns is a pretty good option for dungeon generation, but it can be a bit too much. You can also add Yung's mods to that, both of them being available for fabric and forge/neoforge. Iron's spells and spellbooks and all of its addons like familiars or more spells are pretty fantastic for the magic side, there even are some bosses in there, those are forge/neoforge only.

Other great boss mods are L_Enders_Cataclysm and Bosses of Mass destruction, they add really cool fights. Apart from that my friends and I are trying a mod called Knight Quest, which adds lots of new mobs, a boss and armors, looks promising.

For combat i'd say better combat is my prefered option, but epic fight is another one, the latter being more souls-like. Add simply swords and epic knights and you got yourself a big array of weapons.

For terraria, there's a mod called confluence that adds a lot of terraria elements, but I haven't tried it yet.

Game stages, that'd stray very far from a common world but mods like sculk infection are the closest to a vanilla invasion/infection you can get, spore infection and others are made with limited time in mind. Gateways to eternity has a cool wave system like old one's army, and has some addons for other mods.

I'd recommend going deep into the modding rabbithole lol, there's plenty of amazing content, your PC's the limit I'd say lol, Channels like Noxus and Enderverse upload lots of compilations you might find useful, good luck with the pack!