Harsh Mentor
 
It's unfortunate this guy specifically excludes planeswalkers from the card types he affects - Wizards of the Coast might have avoided having to ban a creature that's not even that powerful in itself. Such is Magic, I suppose. It's also unfortunate that he excludes enchantments, because then I could have made a joke about where the heck was this guy when Glare of Subdual was absolutely everywhere. But regardless, there's hardly a shortage of uses for him, and there are larger casual metagames where he could end up being absolutely oppressive: for instance, imagine trying to fight him with something like Lorwyn's Millfolk archetype.
 
Constructed: 4/5
Casual: 3/5
Limited: 3/5
Multiplayer: 3/5
EDH/Commander: 3/5

Harsh Mentor (5/15)
 
Shortly after getting its first 1R 2/2 (without downside), we get one with major upside. Harsh Mentor is brutal in particular regard to older formats, punishing fetchlands and some of the more powerful artifacts (and creatures, like Deathrite Shaman) by making those abilities hurt a lot more. It’s not an oppressive hate card, but it does a good job of putting the scales in red’s favor; three damage to activate a fetchland makes red decks have an easier time ending the game, and it makes the creature lands a good bit more painful.
 
And, of course, it's a 2/2 for 1R. It scales pretty poorly in the late game, since its combat isn’t great later and your opponent can just smash face (or use planeswalkers, I suppose). But it does work early on, and I can see red using it to help close games out faster.
 
Constructed: 4.25
Casual: 4
Limited: 3.5
Multiplayer: 4.25
Commander: 4.25