The image doesn't work well for me, the last cm or so is corrupted, but maybe that's just my connection. Good first try there, I love the image! The special ability is weird though. What about giving him that 1v1 duel ability instead?
You could also make him a Legendary Creature - Rabbit Rebel, or something.
Also, the official wording for the first ability is
"Whenever (card name) (does something to) a creature, that creature doesn't untap during its controller's next untap step.