As soon as Lambert lunges at him, Strange turns to smoke. He floats towards Lambert, trying to close the distance between them...and just straight up stays in smoke form while the flames shower down on everyone. He's still a little charred because of the inherent magic in Ignatius's attack, but better 'a bit burned' than 'absolutely flashfried'.

Lambert gets a brief second or two to react before, still in smoke form, Strange tries to straight up gas him and send his smoke down Lambert's nose and throat.