Some Magic The Gathering questions?

Question

Q: Do the effects of multiple instances of Hissing Miasma, and Agent of Masks stack?

Q: If a creature with lifelink deals damage to another creature (but not a player) does that damage dealt still become health for it's controller?

Q: In a three way game, can player C defend player B against player A's creatures?

Q: Can you attack yourself?

Q: If -1/-1 Counters build to the point where a creatures power and toughness drops below 0/0, does it die? or does it only die if you attempt to block with it?

Q: Is an enchantment aura card such as Torture attached to one creature only? or is it an independant enchantment (allowing it's controller to target a different creature each turn)

Q: Rimehorn Aurochs have an ability: "Target Creature blocks target creature"

Can you make one attacking creature block another? Or as they're both tapped, can they not be redirected? I assume this means I can make an opponents none-tapped creatures block on my behalf.

Answer 1

1.) If you have multiple Hissing Miasma's, they will each affect the attacking player seperately.  Same goes for the Agent.

2.) Yes, lifelink doesn't care who gets dealt the damage, as long as it deals the damage.

3.) No, you can only block yourself.  But you can play spells such as Fog, Holy Day, or Swords to Plowshares during the attack to stop the attack even though it is not directed at you.

4.) No, you cannot attack yourself.  You can deal damage to yourself though.  If the spell or ability says "Deal damage to target player", then you can choose to do it to yourself.

5.) Once a creatures toughness equals 0, it dies automatically as a State Based Effect.

6.) An aura can only enchant one card at a time.  Once that card leaves play, it goes to the graveyard unless something says for it to move or return to your hand.

7.) Yes, you can force a target creature to block another target creature as long as they are allowed to block.  If the blocking creature is tapped, it cannot block.  If the creature is on the same side as the attacker, then that is illegal so they can't block each other.  But if you are playing a multiplayer game, if someone has a creature that they don't want killed and they are being attacked, you can force that creature to block even though you are not the attacker.

Ex. Player A has Elvish Piper in play and is using it to bring in a big creature.  Player B is attacking with a 2/2 creature.  Player A wants to save the Piper from dying so he is willing to take the 2 damage.  You, as Player C, can force the Piper to block the 2/2 and die before Player A can bring in his big creature.

This works too if you are Player B and Player A does not want to block.