The best part about Fiery Confluence is the fact that it has three modes and you can choose those modes more than once. The three modes are:
- Deal 1 damage to each creature
- Deal 2 damage to each opponent
- Destroy target artifact
That’s quite versatile, especially the third option, which can allow you to destroy up to three target artifacts. In Commander, that’s an awesome ability - seriously, a 3 for 1 is extremely powerful. You can also choose to deal up to 6 damage to your opponents, or deal 1, 2, or 3 damage to each creature (with or without flying!) with the option to hit your opponents in addition or destroy artifacts.
In Legacy, though, there are plenty of artifacts to hit, such as Chalice of the Void. In Vintage there are the Moxen and crazy artifact creatures. As I’ve already said, 4 mana may prove too much for Vintage but in Legacy, a 4 mana spell that can singlehandedly turn the course of a game is pretty darn good. Also, Burn decks are a real deal in Legacy as they are in Modern, and this could prove to be a useful finisher or answer to the aforementioned Chalice or other hate cards in artifact form.
This will definitely find a home in plenty of Commander decks, especially Mono-Red strategies than are looking to burn out opponents. Duplicating a spell like this is a particularly idea, with cards like Reverberate or Blue options like Twincast. The new Blue/Red Commander Mizzix of the Izmagus will find a home for it, as well as many other Blue/Red (Izzet) decks that could cast it for even just 2 Red mana. But the Constructed Legacy implications I think will put this card over the top in terms of value.