A monster's special summon method, unless specifically stated otherwise, is from hand only. You can remove a Light and Dark monster to summon Chaos Sorcerer only while it is in hand.
Plaguespreader Zombie is an example of a monster who can special summon itself from another zone, the graveyard in his case.
As it's effect mentions chaos sorcerer cannot be normal summoned or set.It can only be special summoned by removing from play one light and one dark attribute monsters.
Chaos Sorcerer must be initially summoned from hand. You cannot use his own special summon effect from any other location, like the graveyard. However, if he is properly special summoned by this method, and then destroyed, you are allowed to special summon him from the graveyard using cards like Monster Reborn. Monsters who say "can only be special summoned by..." all work like this, but ones who say "cannot be special summoned except by.." can't use any other method but their own. Lastly, if he's in the graveyard but was not properly summoned (like, his summon was negated, or he was simply discarded there) you can't use Monster Reborn on him.
No. As long as you summoned them properly first, you can keep reviving them from the graveyard as long as you've got a card that can do it.
If you properly Special Summoned him first, and he is then destroyed, you can special summon him back from the graveyard with cards like Monster Reborn. You do not need to remove another Light and Dark monster to do this, and just as important, you cannot remove a Light and Dark monster to special summon him from the graveyard, he can only be summoned from hand by doing that.
Stardust Dragon / Assault Mode cannot be special summoned 'except' by its own effect, or Assault Mode Activate. You are allowed to use Monster Reborn on cards like Chaos Sorcerer, who says it can 'only' be special summoned by a specific way - as long as you do summon it properly this way before it goes to the graveyard. But with the 'except' monsters, that's the only way it can be summoned. You cannot revive it from the graveyard, even if you properly summoned it initially.
The turn player has Priority, so can activate Chaos Sorcerer's effect as chain link 1. Fiendish Chain can be chained to this. Fiendish Chain will resolve first, so Chaos Sorcerer's effect will be negated when it tries to resolve.
Initially, Chaos Sorcerer must be special summoned from hand by following the text on the card. It cannot be special summoned from hand though by any other effect, like that of A Hero Emerges - it can only summon itself using its own method.
Once properly summoned, the Chaos Sorcerer will 'remember' that as long as it is never returned to hand or deck. So if you used Monster Reborn on it, and it was destroyed, you can then use Call of the Haunted on it. But if you were to have it returned to hand, then you cannot discard it and revive it from the graveyard, you will need to resummon it properly first.
Chaos Sorcerer has no practical advantages over the Envoy of the Beginning. The card's value was that it was easily summoned and had a great effect, not as strong as the Envoy but strong enough to be worth including in deck.
Nope sorry. A monster's own special summoning method always refers to when it is in the hand, unless specifically stated otherwise. So you can't let a Chaos Sorcerer summon itself from the graveyard, but Plaguespreader Zombie can.
"Monster Reborn" cannot be used to Special Summon "Rainbow Dark Dragon" from the Graveyard even if the monster was Special Summoned following the conditions on the card before being sent to the Graveyard.That's because it has the text "cannot be special summoned except by", meaning the listed text is the only way it can ever be summoned.This is not to be confused with monsters like Chaos Sorcerer, who says "can only be special summoned by...". These monsters are the ones that can be revived from the graveyard, but only if properly summoned first by their listed method.
The 'Chaos' monsters - Chaos Sorcerer, Chaos Emperor Dragon Envoy of the End, and Black Luster Soldier Envoy of the Beginning must be special summoned initially from hand by removing from play 1 light and 1 dark monster in you graveyard from play. Once you do this, after the monster is destroyed and goes to the graveyard, you can then resummon it using cards like Monster Reborn.