Im going to present my point with a little offtopic story that we had in math:
There is a sheep and there are two lions. The rules are: If a lion eats the sheep he will sleep from this heavy meal and be attackable. And eatable by other lions. You could say he turns into a sheep himself when he eats the sheep. The lions are hungry but they are even more intelligent and like to survive, than they are hungry.
What will happen? If Lion 1 eats the sheep he gets eaten by Lion 2. Since he is more intelligent than hungry, he doesn't eat the sheep. The same is true for Lion 2. Result: The little cute sheep continiues eating grass, undisturbed. YAAY. You can count this up to every number you want (say 100 lions) as long as the number is even.
What I don't like about Nightmare is that it is a hard counter to Fractal.
Take purify: For a long time it did ONLY remove poison. That was even before scorpions were released (That means the ONLY poison cards were: "Poison", "Crysaora" and "Puffer fish" (upped). If you ran into a poison deck: Yaay lucky you, you destroy him by destroying 10 poison counters and he doesn't have any strong attackers. If you did NOT run into a poison deck: Purify is a dead card. An alternative ice bolt can kill chrysaoras, while staying flexible.
Then, purify was buffed and it got that +1 healing counter effect. It is still a counter because: Poison deck, you have 10 poison counters: remove "11" poison counters. Non-poison deck, you have 0 poison counters: remove "1" counter. 10 >> 1: still a counter, a little softened.
Now we have nightmare: Agains Fractal deck: WIN, Non-fractal (much more often case): Dead card. (For me it is dead because "enemy skip one draw while you drew the useless nightmare for
![Darkness :darkness](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/darkness18x18.png)
" << "1 counter of unremovable, unskippable, unjumpable healing for
![Water :water](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/water18x18.png)
")
What happens: You can raise the chance to win against fractal deck significantly but
decrease the chances to all other decks by a little. Or you decide to remove the nightmare, raising your chances and skipping against-fractal-matches which saves you some time.
This is true for all other players and thus nobody uses nightmare. Result: The little cute fractal-deck continiues farming gold, undisturbed.
NOT SO "YAAY"