All of your Dragons, including itself, trigger an enters ability when Scourge is in play to shoot any target for damage equal to the number of Dragons you control
This can be incredible in multiplayer commander as you can be drawing a ton of cards
It is, itself, a 2/2, and it can produce a bunch more 2/2s (likely after a sweeper), so it powers your synergies with Dusk // Dawn, Return of the Wildspeaker, and more
All of those are amazingly good Commander level quality auras
The only problem with these is that the frame feels too contrasting with the gorgeous art on them
Any deck that cares about self-mill will have plenty of options for getting cards into the graveyard, with Sultai-based dredge decks able to capitalize most readily