Yithian Observer 

Trait: Monster - Yithian. 

Prey: lowest cards in hand. 

Forced: If this enemy attacks you, you must discard 1 card at random from your hand. If this is not the case it buffs itself for +1 horror and damage. 

His stats makes this card a pain in the game. 4 Fight is higher than our standard and also its health of 4 is higher. So if you wanna kill this monster in 1 round you must use weapons or spells. Or plan this attack with your team mates, bur watch out if you miss you will hurt the investigator how's engaged with this monster. 

This monster deals 1 damage and 1 horror, but if you can't discard a card it will buff up to 2 damage and 2 horror and that's a lot. 

Offer of Power 

Peril - This is very importent that only the investigator how gets this cards makes the choice! So no team effort. 

Trait: Pact

Revalation: Choose one draw 2 cards and put 2 doom an the agenda or take 2 horror. 

Ok the rules of Arkham are very clear DON'T PUT DOOM TOKENS AN THE AGENDA!! What ever happens please just don't. Especially when the tekst says that this may advance the current agenda! Just take the 2 horror and suck it up.