Bloodthirsty Blade

If the creature doesn't meet any of the above exceptions and can attack, it must attack a player other than the controller of the spell or ability that goaded it if able. If the creature can't attack any of those players but could otherwise attack, it must attack a planeswalker an opponent controls, a battle an opponent controls, or a player who goaded it.

If a creature you control has been goaded by multiple opponents, it must attack one of your opponents that hasn't goaded it, as that fulfills the maximum number of goad requirements. If a creature you control has been goaded by each of your opponents, the creature must attack an opponent (rather than a planeswalker or battle), but you choose which opponent it attacks.

Bloodthirsty Blade has no equip ability. There's normally no way to have it attached to your own creature, although certain combinations of other cards make this possible.

You still control Bloodthirsty Blade while it's equipped to an opponent's creature. You can move it any time you could cast a sorcery; the equipped creature's controller can't.