Specifically it's due to one of the most popular MTG commanders from the set: Vivi Ornitier
Casting him for ten mana is ambitious, but reanimating him from the graveyard is easy enough
Instead, Diviners Wand finds itself in decks that care about cost reduction on activated abilities, since its easy to turn the ability into : Draw a card with the likes of Agatha of the Vile Cauldron
On top of that, he also comes with pseudo-evasion thanks to his tap ability
Rain of Filth Rain of Filth is a mana doubler that comes at a bit of a cost, but you're in black so you'll take power at any cost
Of course, not losing once is ultimately just another form of lifegain and isnt really worth a four-mana investment, but the way the card reads gives it a wow factor that will make people want to play it