Collector Boosters cost 2030, contain 15 cards with guaranteed 5+ rares, multiple foils, and special frame treatmentsaimed at premium collectors, completionists, and resellers who value aesthetic variants and guaranteed high-rarity pulls
Its trigger goes on the stack immediately, letting you target Myr Retriever
I also like this in shells like Discard-Matters combining this with Megrim effects, Reanimation, Midrange that wants card advantage ETB triggers, Blink that wants to have ETB stuff to blink over and over again and +1/+1 Counters-Matter where this is a nice way to add counters onto an ETB body
If a card is put into your graveyard during your turn, you can cast it with flashback if it's legal to do so before any other player can take any actions
Whereas with rituals density leads to chains of explosivity, stax effect density leads to multi-layered constrictions, providing one safeguard after another
As noted, I think Collected Company is rather weak