I understand the basic idea of how echo works, but under what circumstances other than initially summoning a creature does echo have to be paid? As an example, my friend had an Albino Troll in play for a couple of turns (so the echo cost had been paid). I played a card which let me take control of his Albino Troll during his turn (I had several creature control cards in the deck, and I can't remember now which one I used). During my next turn's upkeep, he stated that I had to pay echo on the Troll... and me having no green, into the graveyard he went. Is my friend correct? Also, in what other circumstances does echo need to be paid (he thought if you resurrected your own Echo creature, you'd have to pay echo?) Thanks, as always, for your answers!!