The concept of Zero no Tsukaima is pretty fucking cool. Her spell summons Saito, the seal he's given makes him fucking Bullseye, and his whole shtick is to keep her alive while she charges up her fucking Plot Bomb no Justu Void Magic. The fact that our world keeps shitting out random heavy artillery and WW2-era fighter craft (Zero, get it? Japan u so lol) makes for hilarious RAPE against whatever the bad guys think they have. He has instant mastery over any weapons he gets his hands on, and eventually powers up to make ANYTHNIG a weapon.
They take all that awesome, and then shit all over it with Mai Waifu fucking Harem bullshit. He likes getting whipped and beaten by a fucking flat little cunt while all the big titty chicks try to bang him. He turns them down. Instant fail.