I voted for pulverizer (because
for renewable permanent destruction in a deck that can easily protect it's permanents seems unbalanced). I guess that nerfing in trainer to
when upgraded was well deserved (while pulvy still remains the best rare weapon on par with eternity)
As for black hole, I guess it should be changed to work a bit better against mono/duo and a bit less against rainbows. For example increase it's cost (so that it's less harmful when used against a rainbow in the first few turns), and make it drain at least 10 quanta (so it first tries to drain 3 quanta of each element, then if it was less than 10 it drains the remaining ones from random elements).
As for quint my suggestion is to make it a bit more expensive and make creatures targetable when frozen/stunned by a shield.
And now, that I read suggestions about earthquake, I think they are very reasonable as well. Earthquake would be still a powerful spell, but it would break the synergy of shriekers (very powerful and fast deck) + pillar denial (very powerful in the beginning) = kill quickly while opponent can do nothing
into shriekers (good for aggressive decks) and earthquake (good for control decks), so no synergy
As for the eternity, I guess it is a very versatile card, but not OP in any of it's possible uses. It can be used to deny creatures, but in fact it proves good only against some AI3 and buffing decks. Not so good against FG and PvP.
It can be used to save poisoned or mutated creatures, but the healing is done much cheaper by angels, and having your creatures mutated is not that bad usually.
And as far as anti-deckout use is considered, I guess there will be more ways to deal with it in the future, but anyway nerfing that would only cause people to say '
needs a boost!'
So the nerf in the trainer was not deserved in my opinion, but it is not that bad either, so I won't protest if it stays that way.