Nekroz of Trishula is the ritual version of Trishula, Dragon of the Ice Barrier (you know, that monster so good its still limited to 1 copy per deck to this day?) When this card is ritual summoned you can banish 3 of your opponents cards, one each from their hand, field, and graveyard
The differences are subtle, so inspecting all features together is key to accurate identification
Once per turn, during the End Phase, if this card is in your GY because it was sent there this turn after being Normal Summoned/Set: You can excavate the top 3 cards of your Deck, and if you do, place them on top of the Deck in any order
Case of the Uneaten Feast White lifegain always wants this kind of effect, and getting a turn to do some kind of Lurrus of the Dream-Den/Underworld Breach stuff to get back your Voice of the Blessed that met its fate far too soon is reasonably big game for those decks