Hi experts,

I am thinking that in some cases, it could be desirable for the OL to use blood rage on a monster to sacrifice it. Do you know if this could be done even if the monster cannot attack in that turn (e.g. a melee monster with nobody adjacent to it).

Blood rage reads: " Play this card at the end of your turn and choose a monster. That monster immediately performs 2 attack actions, and is then defeated. " so it seems that the triggering is just end of the turn and chosing a monster.

What do you think?

I would say that valid target is required. But, if the target is defeated during the first attack, the second is lost and the monster is defeated too

It doesn't say that the target should be the same for the 2 attacks IMHO.

I think that the question is more "can an OL play a card only to kill a monster without this monster attacking even once "

As there is a lot of examples of powers where you could trigger them without doing all effects I would say that yes you can play Blood Rage to kill a monster !
the triggering beeing only "at the end of your turn [...] choose a monster."
and as stated with other powers (advance, charge, etc) you can skip some part but not the consequences so the monster would not attack but he will be nevertheless defeated !

https://boardgamegeek.com/thread/2182765/can-we-use-blood-rage-monster-cannot-attack-turn