Can I use Scourge(Servant) + Desolation(Skarn Plot card) cause conditions as below：

A) 1 hero is adjacent to Scourge and suffer 1 fatigue from some ability (like Howl), and
total fatigues suffer ：
A hero 1(monster's ability) + 1 (Desolation) = 2 fatigues
B hero 1(Scourge adjacent A hero) + 1 (Desolation) = 2 fatigues

B) 2 heroes both are adjacent to Scourge and both suffer 1 fatigue from some ability (like Howl), and
total fatigues suffer, and Scourge's ability is activated twice.Overlord chooses Hero A and B each other.
For A Hero's condition：
A hero 1(monster's ability) + 1 (Desolation) = 2 fatigues
B hero 1(Scourge adjacent A hero) + 1 (Desolation) = 2 fatigues

For B Hero's condition：
B hero 1(monster's ability) + 1 (Desolation) = 2 fatigues
A hero 1(Scourge adjacent B hero) + 1 (Desolation) = 2 fatigues

Total A hero suffers 4 fatigues .
And B hero suffers 4 fatigues , too.

C)If I use Word of Misery in condition (B),and their fatigues is equal to stamina：
A hero suffers 4 dmg from 4 fatigues, and 1 fatigue(will transfer 1 dmg) from Word of misery, Will Desolation activate again from word of misery?

D)Uncontrol Power for a mage：
When A mage fails to check on Uncontrol Power , Overlord can use "Surge : suffer 1 fatigue" and " Surge: suffer 1 fatigue and 1 dmg"
Will this will activate Scourge and desolation twice ?

A) Yup

B) I think you're under-suffering there.

Hero A: 1 from howl (+1 from desolation). The OL chooses hero B to suffer 1 from the scourge (+1 from desolation)

Hero B: 1 from howl (+1 from desolation). The OL chooses hero A to suffer 1 from the scourge (+1 from desolation)

That's 4 each.

C) No, it will not.The hero suffered a damage.

D) The surge abilities do not necessarily occur at the same time. Technically speaking, you could treat "suffer 1 fatigue" and "suffer 1 fatigue and 1 damage" as separate instances of fatigue suffering (allowing either the scourge or desolation (or both) to trigger separately for each surge. Practically, your heroes might flip the table.

According to Scourge's text ,if a effect cause suffer a fatigue(s) , another suffers a fatigue.

For condition (B) , can I consider that Desolation is a effect and activates Scourge again ?

In fact , my friend considers that it can loop to die , if 2 heroes are both adjacent to Scourge.

Desolation does not trigger the scourge a second time. Desolation adds 1 fatigue to a fatigue penalty, it does not cause another penalty. In other words, Desolation is a +1, not a separate 1.

Regarding loops, remember that the scourge specifically says it triggers off effects "OTHER THAN THIS ONE", so the scourge does not trigger off of fatigue caused by the scourge.

Just starting a Mists + Chains campaign with my group. It looks like getting the raven is a good choice in addition to the scourge? I'd love to hear anyones experiences on this...

It is very Op and heroes want to flip table....

they just cost 2 points of xp.

Remember, neither "Ties that Bind" nor "Call of Ravens" counts:

1) As XP when purchasing 2 or 3 XP cards

2) As part of your 15 OL cards

They are separate.