Homebrew Drowned Lich Species Details

Drowned Liches are malevolent (unless the player chooses otherwise). 
Corpses revised by the water's gift, they roam the last place they knew looking for vengeance-- Once they've killed everyone they feel is necessary, they retreat back to the waves where they belonged. Players may hear whispers of 'Drown with me' chanted upon the salty air of oceans, or on the spring breeze carried through streams, rivers, or creeks. The typical target for the curse of resurrection are wronged fishermen or sailors, but occasional captains have been known to fall every now and again. The tang of blood and salt is all they know-- All they will ever be. They're crafty survivors known to build armor as well as weapons using scraps from shipwrecks, treasure chests, animal corpses, or even the corpses of their victims.

Resourceful, Strategic, and Cunning; They move fast but plan even faster. Nautical horrors only dreamt of in the minds of madmen, or adventurous scholars who managed to survive the swim back up... 

These creatures are humanoid in figure, and possibly mind-- But monstrous in spirit...In motivation. Once they kill you by either hook or harpoon (base weapon), it is too late. You will become one of them-- One with the smells of blood, rust, decay, salt, moldy wood, moss, seaweed and pure animalistic drive or instinct. 

Drowned Lich Traits

Dark Vision, Gliding Flexibility, Acute Hearing, and Keen Senses.

Legendary Resistance (3/Day)

If the lich fails a saving throw, it can succeed by choice instead. It can cast this check, which can last over the course of three days or three long rests. Once the duration is over, the player will need to recover their necrotic charge by making a sacrifice to the ocean.

Rejunvenation

A Drowned Lich can recover from any injury, specifically a phylactery, within 1d10 days so long as it remains underwater. It regains full health and hit points in its' new form, appearing within 5 feet of the phylactery. It also gains a bonus to its' initiative, stealth, and speed for the first few hours of within being restored.