Kill them all, you´re evil afterall(magic)

You search you mind and find a few nasty dark spells. You find one in particular that you like. It lets you launch "shadowbolts" from your hands that impale oponents. You charge it up and release it against them.

They´re caught completely unaware, they don´t even scream as they´re impaled by multiple black bolts. One of the servants even got impaled by 12 bolts in her torso alone.

You come out of the forest and drag their bodies to the side of the road. There is some blood on the coach, but you can easily clean that off. You reinforce the cracked wheel with magic and then walk over to the horses. There´s four of them, all a simple brown colour and sturdy looking. They don´t seem to like you though, or maybe it was the sudden blood and gore. You´re not really sure.

You could calm them, set them free, Or maybe, you could, Enhance them?