Its a human boar who buffs your mana dorks in addition to untapping them when they attack
The effect will continue affecting that Digimon even if it later gets a digivolution card
Bouncing every one of your opponents permanents can be extremely valuable depending on what youre playing against (such as, for example, Mono-Green Food or Gruul Adventures), and bouncing your own permanents can also be quite good, especially since some of the Giants-centric cards are Sagas (or potentially Yorion, though unfortunately thats not an infinite combo)
We can't get enough of the nostalgia these cards give us, even at the cost of our wallets
All Hallow's Eve This is honestly an obvious number 1
Potential Inclusions for Angels Mutable Explorer 0186_MTGECL_Main: Mutable Explorer Mutable Explorer is every creature type, including an Angel