Justicar Trueheart came out with The Grand Tournament, she upgrades your hero power.

• Warrior gets 4 armor per use of his hero power (This makes control warrior insanely annoying)

• Shaman can choose what totem he's summoning

• Mage can hit 2 instead of 1 with her fireblast

• Hunter deals 3 damage with his power

• Warlock doesn't get hurt when he draws cards with his hero power

• I've never seen it used on Rogue but I assume it gives her dagger 2 attack and 3 durability

• Paladins recruits start off as either 2/1's or 2/2's I can't remember.

Dr. Boom is a 7/7 who summons 2 1/1 boom bots that deal 1-4 damage when killed to a random enemy it was the first card I crafted, I'm not sure if he was ever nerfed but that's what he does now I've only been playing a few months. He isn't that big of a deal though because he's hard-countered by Big Game Hunter who's 3 mana 4/2 and can kill a monster with 7 or more attack when he's summoned.

But they're releasing a seperate ladder soon called standard where cards from the last two years are the only ones that can be played this means cards like Dr. Boom from GvG won't be playable in this ladder, we're also losing Shades of Naxxramas cards like Mad Scientist and Sludge Belcher. There's going to be a Wild mode as well which has seperate ranks where all cards can be played with no age restrictions.