O>O!!!!!!!!
This+Ghostmare=Ultraghostmare
This + Nightmare = Mistake.
Seriously. Why would you use a creature only to prevent it from attacking?
Lol.
Use regular ghostmare, and use this to lock hand, forcing them to either A, deckout, B, Kill them via damage, or C, die of GoTP.
How would this lock their hand? After the nightmare is over (the missed draw) they will either draw their card or receive a card and skip a draw. I see no difference. What am I missing?
PS: I encountered a bug when replying to your post. It started to modify your post. I undid my mistake. I am sorry.
After nightmare, play multiple of these to continually lock the hand up, increasing chances for opponent to discard a Gotp.
Ah.
Would that be too strong?
Well you'd be filling their hand with cards from their deck and decreasing the effectiveness of future nightmares... if you planned ahead and rewound a few GotPs then you could do some major damage, but at that point you have a 4+ card combo so I think it's fine.
It forces them to A, Deckout, B, die by GoTP, or C, deal enough damage with creatures on the field. It's meant to happen near the end of the game, when you only have a few cards, or in the very beginning of the game, so the opponent is starved of quanta.