As the Zealot Hunter enters play and destroys the Deathmaster can the Deathmaster still corrupt and kill the Zealot Hunter sending both to the discard pile?

No. The Zealot's coming-into-play ability is Forced and you cannot respond to Forced actions.

The Deathmaster can destroy something else (if he could normally) in response to the Zealot being played, of course.

Okay, but then he shouldn't be able to kill anyone because that is still responding to the forced action , correct? After Zealot Hunter comes into play, the forced trigger has to resolve before a new action stack can begin, so therefore, the deathmaster would be dead. I guess what I'm trying to figure out, is playing a unit considered an action. (in relation to magic, everything is a spell, even creatures as they are being played and can be responded to by using the stack) But in this game, if playing a unit is considered an action, then in response to that unit being played, you could trigger the deathmaster, then the comes into play forced ability would finally resolve. Sorry, it's hard to explain what I mean.

Yes, playing units, supports or developments are considered actions for the purposes of being able to respond to them.

You can only start action stacks with them though - you can't respond to an action by playing units, supports or developments.

To try and help clarify Clamatius' response, when he said you could use the Deathmaster's ability in response to a Zealot Hunter being played, you would not yet know that the Deathmaster was the target of the Zealot Hunter's ability. You have to respond to the ZH being played, and as it hasn't entered play yet, it's controller has not yet chosen which unit to destroy.

Entropy42 said:

I think you would probably know.