Hello guys

another question!

can the overlord use his overlord cards on lieutenants, like Dash that states "Play this card when activating a monster during your turn." (ie. is a lieutenants considered a monster) or overlord cards like Wristlet of Wind, that states "Play this card on 1 monster group during your turn and keep it in your play area."

basically , is lieutenants considered monsters and being in there own monster group ?

"Lieutenants are represented on the map by lieutenant tokens, but they are treated as monster figures for all purposes—including figure activations, unless specified otherwise... ...Each lieutenant is treated as its own monster group." - Rulebook page 17

So, yes he can be affected by those cards.

Importat point, though, LTs are neither master monsters nor minion monsters, they are just monsters (I am speaking about LTs with LT cards, I've always played that when a master elemetal gets treated as an LT for a quest it retains its "master" status.)

Agents from the plot deck expansions are master monsters of the group they are summoned into.