These characters hail from Final Fantasy IX, which we havent seen any cards from so far, so this would make a lot of sense
Blue and Black both bring some unique effects into a deck, so I can understand them
I think that the Frenzy version is better against black-based midrange decks and ground-based creature decks, so I would say it is better against Rakdos Midrange, Mono White Humans and Rakdos Sacrifice
Refocus, realign, and move to the next step
I heard you like enchantments so this might be easier to maintain for a turn or 2, Infernal Darkness
Grafdiggers Cage, on the other hand, is almost a sideboard staple in the format, as it provides hate against both Dredge and Oath