Hello, I a wondering what happens when Threath from the North is revealed and a burn effect, say Flame Kissed, lower a charachters STR to 0 and kills it, which effect triggers first - the discard from Threath from the North or the kill/burn from say Flame Kissed?

From the FAQ:

"(2.5) Simultaneous but Conflicting Entry into the Moribund State
If a character is killed, discarded, and/or
returned to a player's hand or deck at exactly
the same time, the first player decides which
of the destinations applies for the card's
Moribund state."

So, the First Player will decide whether it the card is killed or discarded.

AH had missed that, thank you!