I disagree with all but
Rakdos Augermage and
Vanish into Memory here (and partially with Cloven Casting because 5 or 6 would be a good casting cost). I disagree mostly because I play these cards in other formats than on their cube evaluations and in their respective formats they are very well positioned.
Heck, you could even say that
Supreme Veredict was a hidden blessing to cubes because you could guarantee that
control decks have access to a wrath effect that nobody else would play (a wrath that dodges Mana Tithe from weenie rush decks, even!) instead of using regular wrath variants that can be easily sideboarded in midrange
x builds and occupying a spot that could be used for another spell for white noncontrolish strategies.
Both
Warleader's Helix and
Grull Ragebeast are well positioned in DGR as a very good removal and an interesting finisher for high-end green decks. In limited especially, it seems that the difference between 3 and 4 toughness is huge. My main concern here is that Ragebeast is not a legend, as RG beasts needs a non-Uril general ASAP.
Lord of Extinction and
Cloven Casting are casual cards that are great in commander. LoE because it is beastly huge in a format and colors that recursion is king and CC because it is an interesting build-around effect that might help some
thematic commanders (its cool because it makes players think about how to abuse it more than because of raw power). The lord was auto-included in my grave cube because it is so huge and is awesome in low-removal environments. It's also a role player in my
Mimeoplasm commander, where it combos with my general and
Triskellion for insta-kills if the game goes too long.
Sire of Extinction is perfectly costed for standard. If it were any cheaper, controlish decks wouldn't be able to do a thing (
Cavern of Souls for demon is a thing even with cmc6). I have it in my test pool for my regular cube to see how much of an effect he has. I don't think it would be better as a 5/5. 6/4 is enough to be a big thread and not enough for you to play/attack blindly. I've also can't get mad at it because I had two cool stories about this guy last friday: Opposing Sire blocking my
Rurik Thar in a draft, making it a huge-risk-high-reward play to stop my creature and enabling a comeback on a very thigh game(we had already split the prize on this one, so we were playing just for fun). Also, in a standard tournament, in the third game of the match, I had an opponent cast a Sire against my (borrowed) Junk Rites only to see me discard
Angel of Serenity and
Rites of Unburial. This prompted store-wide laughter and mockery upon my opponent, which would've won the match if he had played anything else or even sideboarded it out.
I remember both
Rakdos Augermage and
Vanish into Memory having fringe standard play on their time, but neither has an excuse for being so crappy as they were an Invitational and a community-created card.