Let's look at the stock list: Revival Trance is a focused Graveyard deck: I count 19 cards that put creatures into the graveyard either through milling or discarding and 25 cards that care about your graveyard, mostly reanimation but a bit of other stuff too
For example, if a character has Resist +2, then they will take two less damage when challenged
Vigilance Whenever Emet-Selch enters or attacks, draw a card, then discard a card
Given this effect can only happen when Simba banishes a character, however, I imagine many players will opt to skip this particular character in favor of one of Steels many more versatile cards
When these two work together, your opponent is forced to take Moana out all at once rather than chip away at her Willpower, which can be difficult to do
Now this notably affects your own characters as well, but you can build your deck to not be as reliant on songs