When he blows the whistle, rather than a sharp sound... it sounds like a god damn fog horn just went off, the sound making the guards freeze in space as the horrible sounds echos off the walls of the tunnel. Ahead of Kai the ground splits open, fire spilling out and lighting up the tunnel as one massive paw slams to the ground, followed by another. Out of the fissure comes a beast only hell can cook up, a dog larger than Maul, a muzzle full of sharp needle like teeth that seems to be drooling lava. It's massive body is covered in long whispy jet black hair and embers rise off its hide. The heat is intense, even for Kai, as it focuses on the whistle in his hand. Finally its back end comes out and the fissure closes, leaving the beast staring at Kai, waiting.