This should go to the Black Secret forum, as all but the first question are specific to that expansion.
Haven't played a game for a while forgot some moments, and we all know rules are terribly organized.
1. When i as Wu-Feng player roll black die and result is haunt tile i only kill 3 villagers resolving their death effect penalties one by one?
This one pertains to the White Moon expansion, and doesn’t matter whether Wu-Feng rolled the curse or a haunter reached the village. See the White Moon rulebook, page 6, under “Haunting a Tile”:
• if one or more villagers are present on the • tile targeted by the haunting, all these villagers are killed, but the tile remains NOT haunted.
• if no villager is present on the targeted tile, the tile is haunted according to the rule in the basic game.
2. If one of those villagers is from Wu family, their death effect is Bring incarnation in play, so my question is do i put incarnation in hand from incarnation pile or directly in play?
See the Black Secret rulebook, page 5:
One of the level 4 Curses and the death of a member of the Wu family (from the White Moon expansion) have the same effect.
(Wu-Feng icon) Wu-Feng draws 1 Incarnation card, adds it to his hand, then puts into play one Incarnation of his choice.
3. When 3 Wu-Feng Vases are reveled all demons are returned to game?
See the Black Secret rulebook, page 8:
Once the Shadow of Wu-Feng is in play, when the 3 minor Demons present in the Catacombs are returned to Wu-Feng’s board: they may not be summoned for the rest of the game.
(The word “when” in this sentence is an unfortunate translation error; it should be deleted.)
4. When Wu-Feng attacks several Taosists standing on single tile, does -1 Chi applies to all of them?
Wu-Feng rolls the 3 Tao dice, and for each black face rolled, Wu-Feng removes 1 Qi from a Taoist present