Be a DM
Make the Bad guy of the Region a Merchant that sell useful stuff with a trade-off
Create connections with the players so that when they discover he’s the bad guy from the start they are shocked
Have your players try and steal all his stuff and start the fight with the Bad guy in his Dangerous Form 3 sessions ahead of what you predicted
They just wanted the Kart to make it easier to travel around
Players ruin everything. It’d be so much easier to DM without them.