Mindsparker: Punishing people for playing their spells at all doesn't make for fun magic so I don't think it's a cube card. It'll be barely playable in standard as it's a way for aggressive decks that can't play
voice to fight
Azorius Charm,
Sphinx's Revelation, and
Supreme Verdict. As a 3 power first striker it's good against
Thragtusks for as long as that matters. Someone will literally die shortly after playing it in a casual game because it's the first red rare they ever opened and they didn't know any better but their table was vindictive.
Dragon Egg: I like me some red control and the best way for red to have a defensive creature is to threaten to be more dangerous if it's attacked. Still seems slightly weak even for my cube but for the excellent synergy with
Pyroclasm. I hope Theros has a
Pyroclasm but even if it does this thing won't rock boats. I will play it in limited because I always end up in controlling builds with red. I will be wrong to do that sometimes.
Academy Raider: 1/1 for 3 needs some serious upside to be worth it. How many cubes don't run
Looter Il-Kor? Flashback is rotating so it's not even exciting on that axis. Probably barely playable in limited? I would say slightly more than
Rummaging Goblin which was fine but far from great.
Gnawing Zombie: I like sacrifice effects but when they cost mana they have problems. Nevertheless it lets you get value out of chump blocking when you don't have anything better to do and repeatable effects can be quite strong even if they sound weak. I think because of its stats it won't be finishing people off for exactsies very often but when you get to do it it'll be grand. Solid vote for limited (obviously take
Doom Blade first) but I can't see a place for it elsewhere.
Zephyr Charge: I actually like this kind of card for limited. Remember
Dauthi Embrace? Evasion wins games. As long as you remember how much worse than
Kitesail it is in the majority of games you'll be fine. It's relevant that you can jump several beasties to close out a game but that use should be valued below
Sleep and its kin. I'll be picking it whenever I have
Plummet and am in the colors because it's too sweet. Green probably benefits the most from giving individual creatures evasion, too. Anyway it's surprisingly flexible even if none of its modes seem impressive.
Path of Bravery: In most limited games this is actually splashable
anthem with upside when you get to play it on time. It helps win a race if you draw it later although you probably would prefer to draw
Pillarfield Ox in that case; not a stirring endorsement. It might push you a bit into the lifegain deck? I am not sure if the lifegain deck is a thing.
Congregate makes this quite a bit better I think. I wonder if the lifegain theme changes the pick value of
Divine Favor. It's tough to make happen with the only common lifelink in white being at 5 mana - playing black at least gives you access to
Child of Night and
Mark of the Vampire but you want to be green to play your Voracious Wurms... oh wait Soulmender is a card. Okay, it's pretty good in draft and pushes you into the lifegain theme. It still seems tough to assemble the life matters deck though, with none of the cards that give you a bonus for gaining life being common. At least you'll probably survive to play your cards?? I doubt the card is cubeworthy but it's probably worth trying. If you have a tokens theme you can gain a lot of life quickly which could easily turn on the anthem part. Might be a better cube card than
Intangible Virtue just because it goes in more decks.