I don't think the Lich is genocidal. He's way worse: he's omnicidal.
Genocide implies the extermination of one specific group, while omnicide is basically the extermination of every single life form without distinction.

13:10 I think it's somewhat important to make the distinction that the Litch doesn't shapeshift into Billy, he kills Billy, and wears his corpse as a disguise.

It’s interesting to me because genocide (as evil as it is) often connotes a human limitation of stopping at a certain group. But the Lich is more like a force of nature in the sense that he doesn’t discriminate who he kills.

21:00 I never interpreted the scene as Golbetty murking the lich because he displeased her,  I always interpreted it as her ultimately not caring, and striking him down the same way one would a fly making an annoying buzzing sound.

The thing that sets the Lich apart from most Genocidal Villains is he isn't a hothead that throws a tantrum when he is losing; he takes each loss in stride, never wastes time on petty revenge, and worse he LEARNS from each loss and always is looking for the next avenue to his goal.

Finn destroyed his form and stopped him from taking PB's body? That's fine he'll take the Snail as his vessel and wait for the right moment to steal the Enchiridion from Finn. He steals Billy's body to ensure he has a disguise that Finn will never see through given his hero-worship of Billy, uses Finn as his arms and legs to gather the jewels necessary to access Prismo and his Time Room, using Finn again to destroy the Enchiridion to open the portal, and he WINS (at least in one timeline) until Jake got coached by Prismo to retcon his victory. The Lich learned that Prismo will be an issue, so he bides his time observing everything he can and when he hears about another path to ending all life he strikes, killing Prismo's mortal form to ensure his route will be open and Prismo cannot interfere again. On and on until Golb stops him for good at the end of the series, the Lich never stops adapting and trying again until he gets what he wants; never letting a setback slow him down, instead he learns, adapts, and tries again because he is eternal...

The "Fall" and "Stop" speech was fire

The Lich case reminds me of "What If" Infinity Ultron, when he's erased all biological life from his universe and then, having nothing else to do, stood still for eons in complete solitude on a silent cosmos

"before there was time, before there was anything, there was nothing. And before there was nothing, There were monsters" it's insane how that one scene shows how deep the Lich is integrated into the adventure time universe, he is a primordial force that existed before time. If you look at that scene Orgalorg is there as well.

It was always odd to me that the Lich thought extinguishing all life would please a god of chaos.

What’s more chaotic than life on a daily basis? Millions of living things clamoring for resources and space just to exist a little bit longer. Yes death is part of that process but it chaos usually happens in spite of death, not necessarily because of it.

I just had a thought: What if the chaos Golb wants, isn't in normal universes, but Golb's universe, which Golb adds to with those green Tetris lich pieces, that are probably still screaming, but it's only Golb that can hear it

The Lich is the perfect example of a pure evil villain with no under stable or justifiable motives and no redeeming qualities

The Lich’s end is even more horrifying than being killed… he’s still alive… as a skull trapped for eternity in the cube…

My genocidal villain's motivation is to gain enough power to ascend to godhood-- the magic needed for this in theory is INCREDIBLY high and humans don't have any of their own, so he A) outlawed witchcraft, to hog all magical sources to himself and B) decided to kidnap the entire population of a neighbouring (primarily nonhuman species of fire flavoured satyr) country to use their magic blood as fuel (it's a very strong reagent but also. it's blood. not too pleasant to have extracted 24/7), and he also massacred the royal family in secret to get access to the full power of the country in order to do a and b. He's also sending armies of zombies into ANOTHER neighbouring nation to enslave people to produce more reagents for him.

Grimmel shoudlve been a HM, he committed dragon genocide in order to be ennobled a hero among humanity, something Hiccup is the opposite of

‏‪8:16‬‏ Bro, LOOK AT THIS SMILE

I don’t believe it! You’re finally reviewing a villain from something that is not an animated movie! It’s a cartoon! Can you do another one on Codename: Kids Next Door? On how to make a realistic villain again like Father, Grandfather or Cree Lincoln?

For an idea what if the villain forgot their "why" their reason for their actions? Maybe they had caused so much pain and got too caught up, almost loosing purpose and a reason to justify their self.

A LICH VIDEO HELL YEAH

What do you think of this idea for an episode?
How to Write an Irredeemable Villain - Sentinel Prime from “Transformers One”

Their are a few characters like this in doctor who.

Sutekh a god of death, he believes all life is an abomination and he is releasing them into deaths bliss. When asked why not use his powers for good instead of evil and he says "evil? Your evil is my good, i am Sutekh the destoryer where i tread i leave nothing but dust and darkness and i find that good"

The others are the daleks and their creator Davros, the daleks believe anything that isn't pure dalek is wrong. The difference with the daleks is if they won and only the daleks are left they would narrow down on the pure part of their plan. They would as they have before split into factions with small differences, they would keep declaring war on the impure after every victory against themselves. It would become a never ending loop war, genocide, rebuild and war.