It's stille arly yet, but this has been my experience with Ancient Ones.

Yog-Sothoth: Cake. The big deal with Yog-Sothoth is just having enough Clue tokens and spell-casters, so he's pretty easy to beat. I can pretty much assure a victory against Yog-Sothoth with no problems.

Cthulu: Surprisingly easy. Cthulu is a challenge, no doubt, but fairly easy to mange so long as you have Silas.

Aazthoth: Difficult. I'm surprised he's the default choice for new games. He wouldn't be so bad if it weren't for one mystery that requires a clue expenditure while closing a gate of a particular omen symbol; pulling that off once is a good trick let alone multiple times.

Shub-Niggurath: I have still yet to win a game agaisnt SHub-Niggurath. I have tried multiple times with different combinations of investigators, and each time I come up short. Jim, Jacqueline, Lily, Lola, Leo, Silas, everyone just gets pulverized.

I'd say they are about even. For my usual playgroup, Yog is tough but Shub is easy, but that is because we tend to play to crush monsters, where Yog is about collecting spells to solve mysteries. And we also do random investigators, so we never have the optimal team. And then the Mythos deck.

Background: I use semi random investigators chosen first, than a random Ancient one. So I try to pick teams that can do anything given that I don't know who I'm up against. My results for run exactly counter to the OP: The easiest is Azathoth (80% win rate) and the toughest is Yog Sothoth (50% win rate). Of course the sample size is still small (4-5 games per AO) so these values are far from being definitive.

Yog-Sothoth: Cake. The big deal with Yog-Sothoth is just having enough Clue tokens and spell-casters, so he's pretty easy to beat. I can pretty much assure a victory against Yog-Sothoth with no problems.

Nah, you don't play with random pick investigators. With random pick the game become more fun and intriguing. Haven't sense play vs Yog-Sothot with investigator chosen. For me this is cheating

With random pick investigators I found Yog Sothoth to be the easiest. Cthulhu was more of a struggle, but my second victory. I could NOT beat Shub Niggurath with random investigators, I had to choose them carefully to eventually win. Azathoth, it didn't matter what I did. My eventual victory by the skin of my teeth was pure luck.

That was solo games with four investigators. Playing three with two gaming friends we took out Azathoth and Yog Sothoth with ease.

And the one time I played a single investigator I took out Shub Niggurath in about eight turns with Leo Anderson. I attribute that more to lucky draws and rolls, though. I've been scared to try it again.

And the one time I played a single investigator I took out Shub Niggurath in about eight turns with Leo Anderson. I attribute that more to lucky draws and rolls, though. I've been scared to try it again.

I also believe Leo is the best investigator to have against Shub. He can become a strong fighter and he excels in wilderness areas, which can easily defeat one of Shub's mysteries.

But n° of investigator? For me 4 is the easiest scale. I play always in 3, and is perfect

It's stille arly yet, but this has been my experience with Ancient Ones.

Yog-Sothoth: Cake. The big deal with Yog-Sothoth is just having enough Clue tokens and spell-casters, so he's pretty easy to beat. I can pretty much assure a victory against Yog-Sothoth with no problems.

Cthulu: Surprisingly easy. Cthulu is a challenge, no doubt, but fairly easy to mange so long as you have Silas.

Aazthoth: Difficult. I'm surprised he's the default choice for new games. He wouldn't be so bad if it weren't for one mystery that requires a clue expenditure while closing a gate of a particular omen symbol; pulling that off once is a good trick let alone multiple times.

Shub-Niggurath: I have still yet to win a game agaisnt SHub-Niggurath. I have tried multiple times with different combinations of investigators, and each time I come up short. Jim, Jacqueline, Lily, Lola, Leo, Silas, everyone just gets pulverized.

Yog-Sothoth: With the right team basically TOO easy. Keep the gates closed down and Yog is a walk in the park.

Azatoth: About 75% success rate.

Shub-Niggurath: I beat her soloing... once. Otherwise... Nope.

Cthulhu: The hardest.

Yig: Untested at this point.

To me:

Yog-Sothoth - He's the easiest, no doubt. I lost the count of how many times i beat him.

Azathoth - Kind of easy, though there a lot of new research card from forsaken lore which makes the doom track goes down. Last time i fought him, the doom track went down TOO fast and we lost quickly.

Cthullu - The only one AO i manage to beat the 4th mystery so far. Though he's very tough sometimes. New hydra mystery from forsaken lore is one of the toughest mysteries on eldritch horror.

Shub-Niggurath - I only beat her once, she kicked my b*tt all other times.

Yig - Yig, the epic monster himself is easy. But i don't know why everything goes wrong when he is the AO. I haven't won a match against him yet. Yig's serpent crown mystery is the hardest mystery to solve on eldritch horror (at least it's my opinion).

I always choose my investigators, but i 90% of the time roll randomly for the AOs. It's like an RPG, you can create your character, but you don't know what the DM/GM/Storyteller will do, so expect to fight everything.

With Forsaken Lore in the mix and playing mostly solo with four random investigators I've discovered the game is overall more difficult, and my rankings of the AOs are quite different:

Yog Sothoth is still the easiest. Azathoth isn't much worse. Shub Niggurath and Yig can be tough, tense games and are on equal footing. Cthulhu was the toughest, my one victory was by defeating Cthulhu in the fourth mystery AND with no cards left to draw from the mythos. That was a very fun game.

kinda wondering how bad the Posse of Elder Things (I know its not posse but it sticks alot better) will be.