Yes, if you had 10 or more cards when it was deleted, you can activate
cards need to be a two-for-one, or better, and thats never more true than it is in Commander, a multiplayer format, where cards are worth a lot less than they are in a 1v1 format
During the End Phase, after Brain Crusher has destroyed one of the opponent's monsters by battle and sent it to the Graveyard, the one in control of Brain Crusher can Special Summon the destroyed monster to their side of the field
What MTG seems to have over Yu-Gi-Oh is that they don't tend to re-print rare cards in large quantities, lowering their value by a ridiculous amount
Theres one notable exception that I wont be including here, and thats any of the cat demon Rakshasa cards from the Tarkir MTG block and Mahadi, Emporium Master from Commander Legends: Battle for Baldurs Gate
These are due to clarifications that are added after translating from the official Japanese text