Wizards has confirmed that well see seven scenes in the set (with the Battle of Pelennor Fields and Mount Doom both already shown off
Each battle essentially has its own "life total" (like a Planeswalker): attack and damage it enough, and it will flip, transformed into a new card on your side of the table
Either way, those decks are very different from the traditional mill archetype, so I wont be talking about those cards
If youre more into competitive-viable Commander decks, you might be better off checking out some of the precons from the original Commander series like Commander 2017
They can be used just like a regular card even using one promo and one regular version of the same card and won't really provide any benefits
Tashas Hideous Laughter When I read this card, I thought its probably the coolest mill card printed in the last 5 years