Starting the thread with Sigilyph, quite the versatile Pokémon but always a treat. It's perhaps most iconic for the power of its Cosmic Power Flame Orb set in Random Battles which works especially well in a format without team preview and a potential lack of Dark Typs, but that's far from the only thing it can do. With plenty of coverage in Ice, Fire, Grass and STABs it can easily take the role of an all out attacker with the likes of Roost & Magic Guard to abuse good matchups against passive threats, possibly Calm Mind to turn these threats into setup fodder at the cost of coverage. Magic Guard, as good as it is, isn't the only good ability Sigilyph has, it also has Tinted Lens, which is always very fun to run: Tinted Lens Specs with its coverage options and decent power can do some big damage.
So yeah, pretty cool Pokémon in my book.