If youve drawn a card you need to search for, this can be a way to find mana to cast it, but mostly this is a way to sacrifice artifacts you dont want in play anymore, such as a Torpor Orb when youve drawn Dockside, or, my personal favorite use, this can sacrifice Spine of Ish Sah to use it again, or, better yet, sacrifice a Sculpting Steel thats copying a Spine of Ish Sah to get the Sculpting Steel back, which allows you to destroy multiple permanents much more cheaply
It's a staple in red prison decks like Mono Red Moon, but even midrange and tempo decks run it in the sideboard to punish slow or multi-color strategies
Of course, what we mean is that someone should make a list of ten of the best cards in the set for Commander
If your Fortress Kin-Guard enters when Delney is on the field, its enters ability triggers, then Delney triggers that enters ability again
In Near mint condition or better
You might learn some new tricks on your own