Um. It's concealment, and it's total concealment. And the spell description says nothing about it being unidirectional, so we can't target it or vice versa.<br/><br/>Which doesn't impede its breath weapon at all. Or its scent ability. Or its blindsense.<br/><br/>And if we want to be really strict about it, I'm not sure mass resist energy is valid either, since if there's more than 5 feet between us we can't see eachother.<br/><br/>I wasn't going to get into a talk about tactics for the use of cover and concealment until the DM brought up some or all of these points, but since the topic was broached...yeah. This would not have been my first choice for buying time.<br/><br/>On retrospective, I really should have gone with a Major Image of a Red Dragon in the sky to draw that first breath somewhere else.