The most concise way to explain it is to say that indestructible permanents cant be destroyed by lethal damage
Atarkas Command deals 3 damage to each opponent
Magic The Gathering Final Fantasy Limit Break Commander Deck The Magic the Gathering Final Fantasy Limit Break Commander Deck includes the following: 1 Ready-to-play 100-card Commander deck 1 Traditional foil face commander 1 Traditional foil featured commander 98 Non-foil cards 10 Double-sided tokens 1 Collector Booster Sample Pack 1 Reference card 1 Deck box Already hard to get ahold of, and selling for around $120 USD at the time of this writing, the Limit Break Commander Deck is a serious piece of precon hardware
Every example I've touched upon so far would fall into this category, after all
Obvious contenders are Snapcaster Mage and the like - creatures that accrue their value when entering the battlefield or in response to an opponent's attempt at a maneuver, and can then be used to counter a new threat later
Don't worry, even though this deck is Izzet, not Esper, you're still able to cast this card