Lachapelle is a high-peak Saint level monster. She is the Queen Mother of a breed of plant-type monsters that appear as an oasis and live in deserts. She is encountered on the 7th floor of the Necropolis of the Gods in the Southern Sea. She kills a peak level Saint (Karossa) and a Prime Saint (Rutherford) easily, but she is killed by Linley after being immobilized by the other Saints.
Lachapelle appears as a green female humanoid creature. She is 10 meters tall and her body is covered by countless intersecting vines and tendrils of grass. Around her body, there are countless tendrils and vines that are almost 1 kilometer long and are soft green in colour. Her tendrils are larger than that of her children, having the thickness of a human arm.
Lachapelle trains in the Laws of Wind and Water. She is capable of spatial freezing through her mastery of the 'Slow' and 'Fast' aspects of the Laws of Wind and is largely unaffected by the water forbidden-level spell 'Absolute Zero'. Her vines are extremely strong and are very difficult to cut, and so numerous that even getting close to her is near impossible. She manages to easily kill Rutherford and Karossa, even though they were both very powerful Saints. Her vines have great strength and can easily squeeze someone to death, and they can absorb/eat victims that have been enveloped by them, leaving not even bones behind. She is also extremely fast, capable of catching up to Linley in speed while he is still a Saint-level warrior.