Some cards allow you to behold a dragon to get additional benefits, like Sarkhan, Dragon Ascendant, Dispelling Exhale, or even Celestial Reunion if you choose dragons
Not only does Cloud, Ex-SOLDIER incentivize this "everybody gets some equipment" approach, but other legendaries like Barret Wallace and Sephiroth, Fallen Hero reward having multiple equipped creatures on the field
Each Prerelease kit contains everything you need to make a sealed deck, plus a date-stamped promo of a random rare or mythic rare from the set
But, you want that combo later on
Personally, I feel like hes the most exciting design on the list
Completing a dungeon will also allow specific ability text on other cards to be used, with Gloom Stalker and the very meta Dungeon Crawler revealed as two such cards that gain benefits from a completed dungeon - double strike and the option to return to the player's hand from the graveyard respectively