So many people can't read. The card description does not say "Return all monsters on the field to their owners' hands". It says "return CONTROL", so no 🔥 the opponent needs to control your monster first; otherwise why would you need to use this card? Lol.
the first word on the card description is RETURN.
RETURN - verb (used without object)
to go or COME BACK, as to a former place, position, or state.
So if it has to come back, you have to lose it in the first place. So yeah, there's your lesson.
Lost a duel because this card doesnt work, freaking lame
This card can be very useful in combination with mystic box. For example when you encounter suijin, you can summon a weaker monster, then use mystic box to destroy suijin. Activate owners seal to regain control of your monster, then you can enter battle Fase.