It's a special card, but I always try to put my Leoknight in any deck I am playing, if at all possible. Granted, he won't help early in the game, but cmon! Late in any game this guy is worth 5 Knights; I oughta know, I like keeping 3 or 4 Knights in my deck when I can. But Leoknight gets his strength and hps from the number of cards on the field. If both of you have 10 creatures in the game, he gets a 100/100...who can beat that? (Yeah, I know, there are cards that can beat it, like Decoy and a few others....) But if you are looking for strength, Leoknight's your guy! In battle his strength is the number of the opponent's lands X 10 and your hps are the number of your lands X 10. You can see how this guy makes a huge difference in a tough fight.
I agree. Since obtaining Leoknight, I have kept him in nearly every scrap I was in. I think there was one or two exceptions, but I was quick to bring him back in. If you guys can get Leoknight, KEEP him!