Let's see. Adir has the explosives to start a landslide, but that could risk his comrade in this battle. And he could always get close to plant some C4 on the beast itself, but that would risk his life.
At that point, while Grantz goes toe-toe with the giant enemy crab, Adir begins setting some plastic explosives. Filling in the cracks and crevices along the outcropping, sticking detonators into the grey goo.
Once they're readied, he walks to the edge again and shouts "Hey, move back! I'm gonna blow the cliff!" Given that the Shen Gaoren is limping around now, Adir hopes that it will stay still long enough for his plan to work.