@Harlock
Spoiler!
This dungeon is where they will collect the new sacred tree sapling in order to bait the others six houses in this Pierre mess. Using the sapling Pierre will want it and Leon using that against will bet in a deal against him to fight mech against mech but Leon the badass he is will fight without a mech but with specially made gloves. The mech Loen is going to fight is his own mech turned into a spiked head punk style mech. For anyone wondering the bet was if Leon lost he would give Pierre the sacred sapling and if Pierre lost, he HAS to give back Leon's Airship immediately.