These are the rarest cards in these boosters and will likely be pretty valuable, especially for cards like Ancient Tomb
Some commanders directly incentivize this kind of deckbuilding more than others such as Animar, Soul of ElementsAnimar, Soul of Elements, Alesha, Who Smiles at DeathAlesha, Who Smiles at Death, and Uril, the MiststalkerUril, the Miststalker
If youre cracking packs for chase cards, Mega Greninja ex, Mega Floette ex, Mega Pyroar ex, and Mega Dragalge ex are among the big pulls to watch
The card still sees play and still can be very swingy, but graveyard hate in the 21st century has gotten prevalent and sophisticated enough that the card is nowhere near degenerate
Most people get confused and think this means you only mill 30 cards, because you copied Halimar Excavator 5x and there are only 6, but because all creatures enter the battlefield at the same time and "see" each other as Allies, the net effect is to mill 65x6 cards or 180
This is a very 75% card and letting your opponent scry every turn may help them forgive you for swiping their creature