Gravelord Nito is the only covenant master that needs to die in order to finish the story, so if you want to join his covenant, then do so before coming to this point. When you begin the fight, make sure to hurry up and use an Estus Flask, since you drop into the boss area and will lose health. Nito will summon three normal skeletons, which will most likely be your first encounter in the boss area ( a divine weapon will make them stay dead). There are three big skeletons in the back of the area, so unless you want to fight them, stay where you dropped in. Nito has a couple of attacks to watch out for. If he's far away from you and you hear a scream, then he will summon a single gravelord sword out of the ground directly underneath you; if you can see him, he will raise his sword in the air to telegraph this. If you want to dodge this attack, then spam the rolling dodge. Nito can swing his sword horizontally, but if you stay close to him, this will miss you. When he raises his sword above his head, he will slam it on the ground. He can also grab you, so make sure to roll out of the way to avoid this. His most dangerous move is when he curls up and begins to glow, as this means he will release a shockwave that is very large and hard to avoid. If you have any pyromancies or a fire-based weapon, those would be ideal to use in this fight. You don't really want to grab the attention of the three large skeletons in the back, so keep the fight to the front. Make sure to circle around Nito and try and dodge his attacks, while taking shots at him. If you see him about to use his shockwave attack, back up and raise your shield to reduce the damage a little bit.