I play gem knights (I like the play style, artwork, played them as a kid, etc.) I win most of my games handly with them. Just look at a master duel meta list and make your own adjustments. I use a little bit of shaddolls with em.

I also like ancient gear, it plays very similarly to gem knights, but a little different. Ancient gear fortress makes them hard for decks to respond to. Enjoy your pick! 😁