Gogo, Master of Mimicry is really cool, and will be a great add to your Wizard decks, and your Spellslinger decks
Because fetch lands can retrieve any land that meets one of its land type requirements, that same Arid Mesa can fetch a Steam Vents, which is an island mountain dual land
It is part of Theros block
Favored Hoplite Favored Hoplite is a little more evasive with its heroic ability that prevents damage on top of giving it a counter
Hashaton, Scarab's Fist also offers some serious power since its triggered ability doesnt make you exile the cards you copy, as effects like this often do
Since a lot of construct creatures are artifacts, you get an extra +1/+1 for each construct in play