Sometimes its spectacular to watch and play
All five Phyrexian Praetors are getting a double-faced card that transforms into a Saga representing their own take on Phyrexian philosophy
Continuity Cavalcade: Artefacts and Wonders are often a Shout-Out or Mythology Gag to other Final Fantasy games (specifically the first seven that existed when Tactics originally released), mentioning famous characters, locations, terminology, items, etc
He is also fairly broad unlike a lot of the more interesting cards for deck design and so while he is not a must have for a cube he is a good way to make things more complex and interesting
Being able to dig up to four cards deep with Diresight allows you to put what you find into your hand/graveyard right now, no waiting around
If a permanent on the battlefield has in its mana cost, X is 0 when determining its mana value