The "Horse DC hack" Here goes.
1- Get a Chinese Nuker (Easiest) using a nuke with NO SPLASH DAMAGE and NO IMBUE.
2- Have both him and yourself both with a cape.
3- Chinese nuker starts his nuke, the second person summons a horse and the nuke will kill the player on the horse.
4-If timed correctly, the PERSON BEING HIT MUST DIE, and the person will "respawn" on their horse.
5- Now you/him can dismount the horse and it will follow you/him
6- Now this person can spawn a horse, dismount, repeat until they have many horses.
It's a fun glitch and I reccomend you try it xD
Remember, the person being hit by the nuke MUST DIE, and the horse must be summoned WHILE THE NUKE IS "CHARGING".