"Defeat Gravelord Nito"
Gravelord Nito is located past the Catacombs and at the end of The Tomb of the Giants. Note: You must have the Lordvessel in order to reach him.
What you'll need:
Divine Weapon (recommended)
Fire Weapon (recommended, Nito's weakness)
Pyro Spells (Nito's weakness)
Blooming Purple moss clump (just in case)
Sword Swipe-Nito does a left, then right horizontal sword attack, can be blocked.
Overhead Sword Attack-Nito does a strong one-handed vertical strike, can be easily dodged, is blockable.
Grab-Nito's left hand will glow orange and he will lunge at the player, can be dodged by rolling left or right, does a moderate amount of damage if it hits.
Miasma of Death-AoE attack that does moderate damage, unblockable, only way to avoid it is to run outside of the attack radius. Nito will curl up into a ball for a couple seconds before using this attack.
Gravelord Sword Dance-Nito plunges his sword into the ground causing it to re-emerge right underneath the player flinging him into the air, does low damage but builds up toxin level. Generally uses this attack when the player moves out of his melee range, easy to tell it's coming because a scream is heard just before the attack. Cannot be blocked and very hard to dodge.
Skeletal Minions- During the fight Nito will have 3 small skeletons and 3 giant skeletons that will attack the player throughout the fight, killing these minions with a divine weapon will stop them from respawning.
Once you enter the boss room go ahead and drop down the hole, the drop will cause a significant amount of damage so quickly use a flask. Once the fight begins Nito will immediately use his Sword Dance attack and send his 3 small skeletal minions after the player while he slowly makes his way from the left. Pull out a Divine weapon and take care of the small skeletons so they don't come back (If you do not kill them with a Divine weapon they will continue to respawn during the fight making it much more difficult). Now that you have made it a 1v1 fight it becomes much easier, as you're fighting try to stay between where you dropped in and the right side of the room, on the left side are 3 giant skeletons that will attack if you get too close and will easily kill you.
Nito's weakness is fire, so i suggest using your strongest pyro spells and a fire weapon which will easily burn through his HP. Keep in mind Nito is a rather slow moving boss and it takes him a bit to recover from most of his attacks giving you plenty of openings to get some hits in.
Eventually Nito will die and you will be rewarded with 40,000 souls, 1 Lord Soul and the achievement Defeat Gravelord Nito, congratulations!
Edit: If you kill Nito before joining his covenant you will lose the opportunity to join on the current playthrough.