Just like the core FF games, these are powerful artifacts and weapons that buff your heroes with better stats and abilities, and there are plenty of cards that will help you build a party around your items and go digging through your deck for the best ones
Sundering Eruption / Volcanic Fissure Volcanic Fissure means you don't have to miss a landfall trigger, and stir me up some trouble: I really like the first three words on Sundering Eruption
Chernabog looks very static, and sort of sulky, whereas the regular version is more animated and monstrous
My favorites for the Equipment-heavy decks would easily be the affinity for Equipment cards Goldwardens Gambit and Nahiri, Forged in Fire, but well have to see what Equipment enablers are about to get released
Open Cockatrice
Meanwhile, for a Shift 5 character, Pluto Determined Defender is a little underwhelming, with a healing ability that isnt really all that attractive