Brigand plays "One with the dark." In action space one. Now he is in shadows and that was an action. As a reaction he plays "Shadows reach" in action space two. Now he plays "Shadows touch". As part of a "combo". Is this legal to play shadows touch? It is an action and one with the dark is also an action and only one action can be played per hero cycle. Or does the keyword combo over turn this rule of one action per turn? Hope this makes sense. Thanks
Combos don't override the one action per turn rule, I'm afraid. So you can only ever play one action per combo.
Combos let you play multiple cards as "one attack"... so that darkness doesn't activate in between. I also believe that all the cards in a combo would count as one attack for dropping treasure from three simultaneous minion kills (if that's even possible).