I'm reposting this into this section
Could you guys think of extra abilities and effects that you'd like to tag on to other already existing Ancient Ones to amplify them thematically or in terms of difficulty?
Quoth Julia:
"It would be nice having Yog-Sothoth with an ability similar to Daoloth power to switch gate markers on monster surges. This will increase drastically the number of investigators LiTaS. Also, for Yib, as per Tibs league scenario 1, Serpent people do add doomers. Possibly an extended doom track (13) but with the poisonous bite ability of your league Scenario 6. Giving Shub the ability to spawn more Dark young into play (upon monster surges? every time a monster surge happens, place a Dark youn on every open gate, making them not counting against the monster limit). Just a couple of ideas, nothing more"
C'mon guys. Start making some suggestions :')
Maybe something with Quachil and the Mummy monster token?
Ooo... For the Shub suggestion. How about taking out all the Dark Young at the beginning of the game, counting them as spawn monsters (that can't be removed from the board except by combat-- I've forgotten if this is a general rule) and placing 2 of them on a gate whenever it surges? I'm worried that by placing one on every gate on a surge it'll happen too fast.
Okay... Time for some brainstorming...
Eihort- defeating a green bordered monster also causes investigators to gain a brood token.
Ghatanathoa- when an investigator gains clues or a clue, roll a die, on a 1 or 2 flip an additional visage token (i.e. there is a 33% possibility to flip two visage tokens at once when you draw more than one clue). Lloigors move like stalkers and their ability is triggered after they move instead of instead of their movement.
Atlach Nacha- all black bordered monsters become monsters flying, and flying monsters are endless and not counted against the monster limit.
Glaaki- whenever a cultist is defeated, raise the terror level by one.
Nyogtha- whenever a monster is defeated, roll a die, on a one, that investigator must immediately encounter the Tendril of Nyogtha. Investigators defeating a Witch, Warlock, or Ghoul encounter the Tendril on a roll of 1-2 instead.
Rhan Tegoth- Place the Gnoph Keh at the Woods at the start of the game. It is treated as a spawn monster, and moves like a stalker. It moves every mythos phase as if a black square were drawn (if its actual movement is shown, it can move twice). It has two additional toughness. If it is defeated, it returns to the Woods.
Shudde M'ell- Cthonians are not counted against the monster limit. Whenever a cultist moves, roll a die, on a 1-3, search the cup and place a Cthonian on the location the Cultist moved from. During final combat, each investigator must fight a or evade a -1 Awareness Cthonian at the beginning of each round of combat.
Quachil Uttaus- Place the Mummy at The Witch House at the start of the game. It is treated as a spawn monster. It also moves as a fast monster and has an awareness of -3. If it is defeated, return it to The Witch House. Whenever it defeats an investigator, that investigator must draw a dust card. If it causes a sanity loss, all investigators suffer that sanity loss, if it causes a devouring, all investigators are devoured and the game is over. Discard the card as if the first player had drawn it.
Tsathoggua- Investigators only draw two items from the General Store and the Curiosity shop. Formless Spawn do not count against the monster limit. If one appears in the outskirts, place it on The Black Cave instead and replace the one in the outskirts with another draw from the monster cup. After a cultist moves, roll a die, on a 4-6, search the monster cup for a Formless Spawn and place it on the cultist's location. If there is no Formless Spawn in the cup, put a doom token on the Cultist and treat it as a copy of a Formless Spawn that if it is defeated is returned to the cup (rather than being taken as a trophy). If that happens to The Dark Druid, it will still cause all monsters to move when it moves on a black path.
Yibb-Tstll - For each clue token an investigator removes from a location on a board, that investigator loses one sanity. Being driven insane when Yibb-Tstll is the Ancient One causes investigators to draw a madness card, but it does not restore their sanity or prevent them from losing half their clues and items.
Zhar - When his double gate effect is triggered, search the monster cup and box for the two Tcho-Tchos and the Tcho-Tcho Priest (or take them from the board or outskirts if they are in play) and place them on the newly opened gate. They function as a pack that all move together as fast stalkers (game effects that would cause the pack to be separated must be ignored. They must be defeated as a pack or none of the defeated monsters counts as being defeated (don't draw two common items unless all three are defeated, if you only defeat one before being defeated or evading the others, it counts as if you defeated none). They are not counted against the monster limit.
Abhoth-The Children of Abhoth have an Awareness of -1. During final combat, the first player must evade or defeat all three Children of Abhoth before beginning each round of combat.
Chaugnar_Faugn- For each Elder Sign on the board, sealing costs an additional clue (i.e. if there is one elder sign on the board, sealing costs 6 clues, if there are five, sealing costs 10 clues). Tcho Tchos and Tcho Tcho Priest also move like elusive stalkers (except they stalk Elder Signs rather than investigators). If they are on an Elder Sign during the mythos phase, remove it from the board. Curse of the Jungle penalties are cumulative (i.e. you can have a -2 penalty from two elder signs in a neighborhood, and even more if you are also carrying an elder sign).
Bokrug- To remove a being of Ib an investigator must also defeat it in combat. It has a horror check of -2, a combat check of -2, 2 toughness, Weapon Immunity, and if the investigator fails the combat or horror check, they are driven insane or unconscious and the trophies are lost.
Cthugha- Investigators who end their movement in the streets lose one sanity and one stamina. Remove the fire vampires from the cup at the beginning of the game. Fire vampires are not counted against the monster limit and are treated as spawn monsters. Whenever there is a gate surge, place a fire vampire on the surging gate. If there is no fire vampire left to be placed, all investigators in Arkham lose two stamina.
Y'Golonac- Cultists are stalkers. Using a tome causes an investigator to reduce maximum sanity by one, but the investigator who read the tome also gains one additional clue token.
Though Ithaqua and Cthugha are really very similar to each other, so it makes sense that their abilities would overlap somewhat.