After getting the Telekinesis+2 ability, go to Cyseal. Go on the road northwest of the market square. Look for a large beer barrel on stilts behind some wooden barriers and up some steps. Once there, switch to your secondary character and place the barrel in their inventory. The barrel will overburden that character, making them unable to move. Switch back to your main character and leave the secondary character with the barrel. Get into a random encounter outside Cyseal. During combat, open your inventory menu and send the Beer Barrel to your main character. Take the barrel out of your inventory, then use Telekinesis+2 to slam it into your enemies and instantly kill them. All enemies from random encounters in the overworld map can be killed using this method.