Today when I used swallow for the first time it was against the Tank (Melee only) with a Guard action on. The attack originated from 3 spaces away and succeeded. Since the Melee user wasn't adjacent to the monster was he able to use his guard as soon as he was swallowed? I'm guessing yes since guard can be used to interupt any of the Overlords actions (obviously within the restriction limits of the stomach) which means while he couldn't attack before he was swallowed he could after? Even if it was my last attack and my turn ended as soon as the monster finished swallowing the hero? He was only able to roll one red die but since he rolled an X I wasn't worried about clarifying this.
Though I have to say, Swallow reduced Nanok down to 5 wounds from 22, I enjoyed that.