Mirrorpool

01/22/16

Any enters-the-battlefield abilities of the copied creature will trigger when the token enters the battlefield. Any “as [this permanent] enters the battlefield” or “[this permanent] enters the battlefield with” abilities of the copied creature will also work.

01/22/16

For Mirrorpool’s last ability, the token copies exactly what’s printed on the original creature and nothing else (unless that creature is copying something else; see below). It doesn’t copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.

01/22/16

If the copied creature has in its mana cost, X is 0.

01/22/16

If the copied spell has an X whose value was determined as it was cast (like Fall of the Titans does), the copy has the same value of X.

01/22/16

Mirrorpool’s third ability can target (and copy) any instant or sorcery spell, not just one with targets.

01/22/16

The copy will have the same targets as the spell it’s copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If, for one of the targets, you can’t choose a new legal target, then it remains unchanged (even if the current target is illegal).