Bastion has upgraded his Deck, by which I mean he’s using his manga cards and a bunch of other Zombie support cards.
This is a standard Roaming Duelist event. Dueling in Duel World (but not the Gate) and Ranked Duels increases the chances of him appearing.
His drops include “Shutendoji” and “Red Ogre” from the manga, as well as various “Chemicritter” monsters and “Goblin Elite Attack Force”. The cards are also available via completing event missions.