In certain scenarios, lieutenants don't die, but are rather knocked out instead.

Can a monster revive a knocked out lieutenants? There is nothing in the rules mentioning monsters may revive a lieutenant, but I figured that it may be implied.

The rules for the quest tell you how to recover hearts on your knocked out lieutenant. Most of the time the lieutenant can only preform a stand up action.

Which quest are you talking about specifically?

The rules for the quest tell you how to recover hearts on your knocked out lieutenant. Most of the time the lieutenant can only preform a stand up action.

Which quest are you talking about specifically?

Well rules mainly say treat the knocked down rules the same. Problem is rule book does not take into account the scenarios in which Lieutenants can get knocked down and thus does not mention anything about reviving.

I am mainly referring to Through the Mists quest with Splig. It seems a bit broken if monsters revive him as you essentially take away both his actions just by knocking him down repeatedly. Serena is able to be revived and therefore have both actions, but if you knock out splig, he essentially loses an entire turn.

There is a list of actions that monsters are allowed to perform on page 11 of the core rulebook. Revive is not one of them. Therefore no, monsters may not revive a KO'd LT, unless the quest rules specifically say they can.