Centaur is the best card in the game for me. With first strike, no land requirement and any item used going back into the book it's got a lot of things going for it. Especially good with the yellow pendant that gives st+10 and hp+10, critical hit and permanent hp boost at end of battle. I just use that over and over. Pretty soon the centaur is unbeatable.
I was fortunate to have about 3 of them, but in certain battles, I could only have 1 or 2 because I needed balance. The first strike and the weapon return is a step better than the Harpy and Lizard Man. Centaur has earned a rightful place in my deck.