If I activate DDV and my opp. has dreamaster in his hand, does it die? What about other monsters with ???? atk like wicked erasor?

I attack with my magician of faith and activate magicians circle and my opp. chains to mirror force, since mirror force was last, wouldn't mirror force kill my Mof then magicians circle kicks in so I can atk with the other monster? Or does it resolve after the circle resolves?

Monsters with "?" for ATK are treated as having an ATK of zero for this effect, while they are in the hand or face-down.

But in regards to your second question:

Mirror Force destroys all attack position monsters so the chain would resolve like
this

1. Magician's Circle resolves you to special summon a Spellcaster with 2000 or less attack (i am assuming it is in attack position)
2. Mirror Force resolves destroying all attack position monsters on your side of the field.

The best thing to do in this position would be to special summon it in defense position unless the card states other wise

Wanted to point out two things:

1 - You misunderstood the chain. Chain link 1 was Magician's Circle, not Mirror Force. So Mirror Force would destroy the Magician of Faith, and then M. Circle would special summon the spell-casters. (I know it was a little confusing based on how they wrote it).

2 - Magician's Circle summons in atk mode, not defense.

lol thanks sorry bout that getting a bit tired now its 1.48 am here lmao

I am wondering also...

You can't solemn when Nepthys gets special summoned by hand of nepthys right? Since it was through a card effect?

Correct.

The effect that special summons the monster must be negated in order for the phoenix to not be summoned.

Divine Wrath will do the job.

I was just giving a situation that's all, i didn't want to take time and think of a spellcaster or w/e. I just thought of one that popped in my head, should have said breaker, but anyways <_<..I've killed someone with MoF before @_@. Also another Q.

Triangle Power states that normal monsters level 1 get 2000 atk power. At the end normal monsters die, so the Q. is, even ones I summon after I use the spell card?