Bunch of Questions

[The1337Magician]

1. Can you aura enchant a keyrune and if so does it stay on it when it goes back to an artifact?
2. Does  {Ground Seal} break  {Lazav, Dimir Mastermind}?
3. If I hit a planeswalker with a ciphered creature do I cast a copy? For example,  {Hands of Binding}. Does it cast and fizzle or does it target the planeswalker's controller?

[Keyeto]

1) You can enchant it while its a creature, but it will fall off once its no longer a creature (unless its an enchant permanent).

2) No, because Lazav doesn't target anything.

3) You have to deal combat damage to a player, a planeswalker does not count.

RESOLVED

[The1337Magician]

3) You have to deal combat damage to a player, a planeswalker does not count.

But aren't planeswalker's considered players in some conditions?

[Kaleo42]

Nope. You probably thinking of {searing spear} hitting a walker. Actually what happens there is you target the player and just like with combat you anounce an intent to redirect that damage (attackers in the combat example) to the walker as you cast the spell (declare attackers). This means {witchbane orb} protects walkers from {searing spear}.