Jenova essentially makes any sacrifice cards that you're running extra powerful thanks to her second ability
That said, it's susceptible to bounce and exile effects
Since you'll be gaining life very early on, you'll likely have a ton of excess life by the time you bring out Bolas's Citadel, as it does cost three generic and three Black Mana to play
This keeps you from using them indefinitely, so make sure youre certain about the deck and cards you want before spending wildcards
They come in and trigger effects on each turn like a saga, but while they're on the field can also block and attack and behave as normal creatures
The back half of this battle, Zilortha, Apex of Ikoria, makes itself and the creature you tutored for (and all of your other non-humans!) effectively unblockable