Echo and theft

[clavio]

Opponent plays a creature with Echo

I steal creature with Shackles

Does the creature die during my upkeep if I do not pay the echo cost?

[Bovinious]

"You" on a card refers to the cards current controller, which is now you because of the shackles, so according to the rules text on echo: At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.

So yes, you will have to pay the echo or sac the creature, which would of course go to its owners GY.

[quicksilver]

Important to note you would have to pay the echo no matter when you stole the creature, even if it's origional owner had already payed the initial echo since you pay echo the turn after it comes under your control, not just the turn after you play it. And if he got his creature back he'd have to pay echo for it yet again.

[mercenarybdu]

Of course you have to pay the echo costs as you are now the new controller so if ya don't have the mana to keep it then you just helped yourself to a free kill.