When you can spectate, you have access to all hidden zones in the game (basically players hands, cards that are face-down, or exiled face-down cards)
The only drawback to Brightstone Ritual is that you need to be running a decent amount of goblins in your deck to get decent mileage out of it, and it's best used in a goblin tribal build
This version of Liliana can provide some life drain with her passive ability, fill our graveyard with her +1 ability, and all but end most games with her -8 ability
Owing to the typically higher mana cost of Dragons than that of Zombies, this card also comes with an increased mana cost in comparison to its predessor
The explore mechanic pulls double duty in the deck and offers a repeatable source of card advantage, lands, and a way to build threats