Qustion on the two of them… When do I have to play them? Can I play them at any time during a monster's turn or before I start using that monster?

It's been clarified you can use them anytime during a monster's activation.

Thanks to that clarification, Frenzy may make you overrun too : double move and then attack with frenzy.

Is there anything preventing use of two dashes on a same monster of lieutenant on a same turn ?

kalle said:

"Two Overlord cards with the same name cannot be played on the same target in response to the same triggering condition."

RagsMckay said:

But there isn't anything triggering those dashes, or is there ? I sort of thought that triggering thing to mean things like entering an empty space or something similar. But having two dashes to a lieutenant in some encounters is really strong, so I'd like to see something preventing the double dashing.

The trigger for a card is when the card says you can play it. I beleive the Dash card states to play at the start of the monster's turn. So the trigger is the start of the monster's turn, as that is what triggers the ability to play the card.

Trigger for Dash (and Frenzy, no double-Frenzy either) is "Play this card when you are activating a monster during your turn." You don't double-activate monsters, so one Dash per activation.

Dam said:

Thanks for making this crystal clear I believe You have it right, I just didn't understand it from the rules.