Then these surveil 1 on arrival to the battlefield, so they can give you card draw security, and then also send it to the graveyard if you don't immediately need it, or just want reanimation, flashback or delirium for later use
Vraan, Executioner Thane Vraan, Executioner Thane can add a little bit of extra kick to cards like Blood Artist, but it isnt too effective because its limited to only one trigger per turn
It's an instant, and if you have the mana available after a board wipe, you can get your creatures back before you are attacked by one of your opponents
Similarly to Seven Dwarves from Throne of Eldraine, Nazgl allows players to break a formats deckbuilding rules
Why not game design
The word if in the text of the triggered ability, and the very condition its on the battlefield tell us that this ability is conditional