Spawn creator Todd McFarlane’s take on Nidhogg is in Lord of Arcana. The fearsome dragon is one of the game’s "angry" looking bosses shown in this trailer. McFarlane’s Nidhogg was also in Lord of Vermillion. That piece of art on the right is from the Japan-only arcade game.
Yoshitaka Amano did the artwork for Agni and Takemikazuchi is an illustration drawn by Tetsuya Nomura. Watch the trailer to see these and some of the armor you can customize your slayer with.