Black has some great additions for my Blood Artist deck. Let's check out Red.
Arthertorch Renegade: Interesting, and a great card to learn the Energy economy with. It reads like a solid uncommon, especially if you have a lot of Energy laying around.
Fateful Showdown: I am so not a fan of this 'cards in your hand' nonsense. I play Magic to play the cards in my hand. Junk rare for sure. Count the number of 'cards in your hand' cards in a set. That's the Saviors of Kamigawa ugly stick for a set. If the number is five or greater, that's a really bad sign for the set.
Brazen Scourge: Solid, clean. Now we need a Gremlin tribal deck.
Furious Reprisal: great for multiplayer, lame everywhere else. In Constructed it reads 'deals 2 damage to target creature and/or player.'
Built to Smash: great Red Deck Wins buffer. I am playing it in more than just RDW.
Chandra, Torch of Defiance: It costs four mana, and it has four abilities. That's what Jace, the Mind Sculptor is like. But the comparisons end there. JTMS has a 0 ability that is a repeatable Brainstorm, and the +2 ability can break the back of most combo decks. After a few turns, if JTMS is not answered, it pretty much takes over the game on his way to an ultimate. Let's look at this Chandra with that in mind. The +1 is good, but it's not a +2. You still have to have mana to cast the card you exiled, and if you don't, all you have is a way to ping for 2. 'each opponent' means that Chandra can be a great EDH card. The +1 that gives you two mana is very good. The -3 ability is great for creature removal in Standard, and not so great in formats that don't play on a lot of creatures (Modern, Legacy, and Vintage). The ultimate is good, but not if your opponent has ways to get a ton of life. There are better ultimates. In summary, this is a Standard all-star like previous Standard all-star planeswalkers, but by itself it is nowhere near the power level of JTMS, and that's fine. Who needs a card everyone has to get a playset of to play Standard. That would be lame.
Cathartic Reunion: Lovely art work. Great with a ton of Flashback, which Legacy has. It's also good in all other formats in a deck that has the ability to cycle through the graveyard. You have to discard first, and that's important. Still, you are only paying two mana.
Chandra's Pyrohelix: Limited battle trick, useful in battlecruiser Red Deck (Sometimes) Wins.
Giant Spectacle: Useful in more than just Limited.
Combustible Gearhulk: Now this one is close in power to the White one. The blue and black Gearhulks feel like at a lower power level. This is a great card because it makes you think, and makes your opponent think. If you play it in Red/Green, where you have access to a ton of mana and are packing some heavy critters, the right three cards in the graveyard option can win you the game, and in your hand can also win you the game. I really want to build around this card.
Demolish: A classic reprint. Needed in most sets, and even more so in an artifacts-matter set.
Harnessed Lightning: Replacement for Lightning Strike from Theros and Origins. One Energy is 1 damage based on this card.
Hijack: A better Act of Treason (only creatures). Is that so? Nice! This is a great common.
Inventor's Apprentice: A very good uncommon. I am surprised. It's a 2/3 for 1 mana.... wow!
Incendiary Sabotage: A really good uncommon. In this format, you should have plenty of artifacts to sacrifice, and then you can swipe for 3. Nice! Anger of the Gods from Theros was much better, though, since you didn't need to sacrifice anything and if you killed the creature you got to exile it.
Lathnu Hellion: Reads like a junk rare. You need to keep pumping Energy into it to let it live.
Madcap Experiment: Any artifact? And I don't have to pay the mana cost? That's insane power, even as a four drop. You better have lots of artifacts, though, otherwise, this could cost you the game. It reads like a junk rare, which is awesome, because I really want to build a Johnny deck around it.
Reckless Fireweaver: Great in multiplayer and not bad elsewhere. It deals the damage to your opponent, and that can be a way to keep an opponent's planeswalker in check. Not bad, I say.
Maulfist Doorbuster: That's a very reasonable card. On its own you can make it unblockable twice, and it deals 4. That's respectable. I like it a lot.
Renegade Tactics: Solid one drop. I want to play it. Strong in a creature-heavy Standard.
Pia Nalaar: It reads OK, but it doesn't have anything that screams Legendary to me. Plenty of creatures have the 'mana for boost' clause, and when you sacrifice an artifact... well, you are sacrificing an artifact. It doesn't feel like a strong card.
Ruinous Gremlin: Great one drop in Limited.
Quicksmith Genius: A solid uncommon in a broader strategy. You would need a way to use the cards you are discarding. I wish Flashback had made a flashback in the previous block. I feel that was a miss.
Salivating Gremlins: Solid common, especially in Limited.
Skyship Stalker: A junk rare. Think of it this way: give it three red mana, and you have a 2RRRRR creature that is a 4/3 with First Strike and Haste. That, my friends, is weak. That's a Limited jank 6 drop 4/3. Now, late game, the lameness evaporates and you have a mana sink that can be quite the beater. If you have six mana laying around, you will have a 4 drop that is a 7/3 with First Strike and Haste. That's pretty good. A bomb in Limited, and a casual super fun card elsewhere.
Speedway Fanatic: A block card. Useful in Limited and also in Standard. Still a good 2 drop 2/1 with Haste even if you don't have any Vehicles.
Spark of Creativity: Great title. This card goes great with Scry. That way you already know the converted mana cost of the top card of your library. If it's a land, though, you may get to play it. I want to see this card in action. It looks like a tool against mana screw.
Spireside Infiltrator: Another great card for multiplayer. The 1 damage ping is not as great against a single opponent. Still, it reads like an useful Limited card.
Spontaneous Artist: Useful Limited card.
Territorial Gorger: Nice use of Energy. It reads like a landfall card, but for Energy. It could be really strong if you are playing a deck with ,any ETB Energy gainers. Still, it reads like a junk rare.
Terror of the Fairgrounds: Limited jank. Gremlins are the Minotaurs of this block.
Start Your Engines: Good recovery after a board wipe when all your vehicles are just sitting there like equipment.
Thriving Grubs: Not bad. I see it being useful in Limited, and to get up to a reasonable creature count in a Gremlins deck.
Welding Sparks: Solid creature removal even when you are controlling a small number of artifacts.
Wayward Giant: Limited jank. Menace is nice on pretty much any card.