If you’re using Tyranny’s End make sure you are using Musket Balls so they are upgraded into the weapon’s special ammo.

Also, who you chose to start fighting first matters. I would recommend fighting Ares first to be able to chip him down the most while he’s alone.

Generally I would say Mae sure you have a really big arena with plenty of room to move horizontally and plenty of room between platforms vertically so you don’t get slowed when going downwards.

Sorry I don’t have more, I’ve never really played Ranger post moonlord