Many creatures and artifacts can benefit from this, from Atsushi the Blazing Sky to Spine of Ish Sah or Meteor Golem
Contractual Safeguard is an instant that gives a creature the player controls a shield counter if it's cast during the main phase, and can duplicate one type of counter on a creature and give it to each other creature the player controls
That works multiple times, for as many Detectives as you can play that turn
The card itself is remarkable for enabling token strategies, but the key here might be just how it can easily turn a Commander game into just how much Nuka-Cola you can guzzle in a turn
Anywhoos - onto the announcement : Call Forth the Dead
Getting a relevant enchantment left behind when you wipe the board feels great, and this spell should see play in a wide number of decks, from Aristocrats to Enchantress