Carmen, Cruel Skymarcher Carmen, Cruel Skymarcher lends itself well to a grindy sacrifice deck that slows things down to make the most of Carmens powerful attack trigger
Cyberdark variants have interesting synergy with the card as well, because there are a few compatible LIGHT and DARK Level 3 or lower Dragons, like Galaxy Serpent or Hunter Dragon
Perpetual Frowner: Jaden from episode 134 up til the end of the show frowns MUCH more than he smiles due to trauma
Kelsiens ability to ping a creature and gain experience when it dies is easy to break with a simple Basilisk Collar, and its vigilance means you can declare it as an attacker and still use the effect to one-shot a troublesome blocker
When a limited event ends, theres no way to get the cards afterwards, so make sure you keep playing to get the cards you want
Rather than being format staples, the ideal life for a hate card or hoser is to lurk on the fringes of the format, mostly unplayed, waiting to show up in sideboards and play the hero if a certain theme or card suddenly becomes way too good for the format