Question for the masses: I am being told that this card can stack. Meaning if you cast it & tap their only creature than hit with the creature it is ciphered onto you can cast the copy on that same one creature & it doesn't untap during the next TWO untap steps
{hands of binding}
No it doesn't stack because the wording is still "your next upkeep"
It doesn't stack, as both effects say "the next untap step". Effectively, it will have both stances of "doesn't untap during the next untap step", but both referring to the same untap step. You can keep this indefinitely though, as you can re-apply it on your next turn if he doesn't put another creature down or stop yours from attacking