Mickey Mouse Food Fight Defender is excellent here, or the new Clarabelle Clumsy Guest also give you some flexibility against items
My Final Fantasy XIV fangirl heart is overjoyed at the inclusion of an Emet-Selch card, as well as other familiar faces like Kefka from FFVI and Sephiroth from FFVII
If you mean 'challenging' other characters, or glimmers, in play Steel and Ruby are good at challenging and can get benefits for banishing opposing characters during challenges
Gogo, Master of MimicryGogo, Master of Mimicry Gogo, Master of MimicryGogo, Master of Mimicry's ability to copy activated or triggered abilities you control X times is exactly the sort of thing combo fans are going to be thrilled to explore when building their Gogo decks
However, weve already been given a glimpse at alternate art forms of cards, bringing the total number to well beyond that 204 number for sure
Seymour Guado (Kinnan, Bonder Prodigy) The best things you can do in Commander are drawing cards and generating mana