l am about to have a Final Battle with Hauster, just two things l need confirmation on.

1) Hausters combat rating is X being the total of the Terror level, in my game the Terror level is still 0, is his combat rating 0.

2) Hausters card Attack is a gradual reduction in Luck Skills, on page 22 of the main rulebook in The Final Battle no3 Ancient One Attacks there is a For example which states Hauster forces all the investigators to make an increasingly difficult Will check or lose Sanity.Is the card correct (Luck) or the rulebook (Will).

Yes, if your terror is 0, then his combat modifier is 0.

Also, I would believe the card is correct. Not just because it's on the card, but if you notice, other than Cthulu and Azathoth, each of the other 6 base game AOs have you make a check on each of the 6 different skills. If Hastur is supposed to be Will, then you would have 2 that use Will checks and none use Luck.