Endgame+ adds new End armor stronger than netherite, It also adds some new mobs like the Ender Zombie whom which has a ton of Hp and has new drops. This mod also adds a new villager called the "Champion" who will sell things like beacons for a hefty price! There are more things like the End Assassin boss which has as much health as the Wither! Or there is the Ender creeper which is 10x as strong as a charged creeper!
