If it is not specifically denied, then yes. For example, if Stardust Dragon is removed from play, you can Special Summon it by using a card such as D.D.R. - Different Dimension Reincarnation.
Almost all Synchro Monsters specify "One Tuner + one or more non-Tuner monsters" or similar. However XX-Saber Gottoms does not, as well as a Tuner, he just requires Earth monsters as components, these can be Earth attribute Tuners if you wish. Also, Red Nova Dragon has two tuners as a requirement.
Synchro Monsters can be summoned from the Extra Deck (formally known as the Fusion Deck) by a Synchro Summon.A Synchro Summon can only be performed with one Tuner Monster and one or more face-up, non-Tuner monsters you control (with XX-Saber Gottoms as the exception, who can be Synchro Summoned with more than one Tuner Monster). You can tell if a monster is a Tuner by looking at the card type and seeing "/Tuner" next to it. For example, you can tell Junk Synchron is a Tuner since its card text shows "[Warrior/Tuner]".In order to Synchro Summon a Synchro Monster, the Levels of the monsters used must equal the Level of the Synchro Monster. For example, Gaia Knight - the Force of the Earth is a Level 6 Synchro Monster. That means Junk Synchron, a Level 3 monster, would need a monster(s) whose Level equals 3 to Synchro Summon that Synchro Monster (or any other Level 6 Synchro Monster for that matter). Once you have met the requirements, you can send the monsters from the field to the Graveyard and Synchro Summon the Synchro Monster (this still counts as a Special Summon).Just remember, unlike Gaia Knight - the Force of the Earth, who doesn't have any specific requirements besides a combined Level of 6, some other Synchro Monsters do. Some require specific Types, Attributes, Archetypes or monsters to be used.
If it was properly summoned by Synchro Summon, then yes, it can be brought back, assuming it has no other restrictions. That means if it got to the graveyard in any other way (ie, tried to Synchro Summon, but it was negated, or it was 'only' special summoned by Vayu, or was sent there by Gale Dogra), then it can't be reborn.
Generally, the only way to Synchro Summon is by sending monsters from the field to the Graveyard. There may be some cards that allow you to Synchro Summon with cards from the hand, such as Eccentric Boy, or Special Summon a Synchro Monster with cards from the Graveyard, such as Blackwing - Vayu the Emblem of Honor.Eccentric BoyAttribute: WINDType: Spellcaster/Tuner/EffectLevel: 3ATK: 800DEF: 200When using this card as a Synchro Material Monster, the other Synchro Material Monsters is 1 monster in your hand. The Synchro Monster that used this card as a Synchro Material Monster cannot activate its effect, its effect(s) is negated, and is removed from play when removed from the field.Blackwing - Vayu the Emblem of HonorAttribute: DARKType: Winged Beast/Tuner/EffectLevel: 1ATK: 800DEF: 0If this card is face-up on the field, you cannot use it for a Synchro Summon. If this card is in your Graveyard, you can remove from play this card plus 1 non-Tuner "Blackwing" monster in your Graveyard, and Special Summon 1 "Blackwing" Synchro Monster from your Extra Deck whose Level equals the total Levels of the removed monsters. The effect(s) of that Synchro Monster is negated.Note that this is treated as a SPECIAL SUMMON, not a Synchro Summon.
Yes, unless the Synchro Monster is removed from play, negates spell cards that target it, etc.
Of course not. They can only be Synchro Summoned, or Special Summoned under a few circumstances, like Starlight Road, or cards like Call of the Haunted, if you properly Synchro Summon it first and it then goes to the graveyard.
As long as they were properly summoned first (ie, successfully reached the field due to a Synchro Summon) then yes, you can summon them from the graveyard with cards like Call of the Haunted.
You are allowed to use Monster Reborn and similar cards, under most circumstances. The important thing is that the Synchro Monster must have been properly special summoned first. If the Synchro Monster ever goes to the graveyard without being properly summoned by Synchro Summon (ie, Starlight Road can do this) then the Synchro Monster cannot be revived like that. Similarly, if a Synchro Monster had its summon negated, it also can't be brought back from the graveyard. Last thing to consider is some might say "cannot be special summoned except by Synchro Summon" meaning the only way to summon it is by Synchro Summon, there is no other way, even if it was properly summoned first.
The Sky Scourge monsters say they "Cannot be special summoned except by". The only way to ever special summon them is to follow the text on their cards. Even if you did properly special summon them, they cannot be revived from the graveyard or removed from play zone. That is the ruling regarding 'except by...' monsters. This is not to be confused with "only be special summoned by.." monsters like Chaos Sorcerer, but also Synchro Monsters too. If these are properly special summoned first, they can be brought back by cards like Monster Reborn or Return from the Different Dimension. But barring a few extreme circumstances, there's no way to special summon the 'except by..' monsters in any other way apart from their printed text.
If the monster is a 'special summon only' monster, then it can be revived from the graveyard by cards like Monster Reborn, only if the monster was properly special summoned by the listed methods. Synchro, Ritual and Fusion monsters count, and are considered properly summoned when Synchro, Ritual or Fusion Summoned. In the case of Fusion Monsters who can't be Fusion Summoned (XYZ fusions, Gladiator Beast Gyzarus), then simply following the text is enough to count as properly summoning it. Examples of 'improperly' summoning them would by Cyber Stein, and Starlight Road, as these do not Fusion/Synchro Summon. If the monster says 'cannot be special summoned except by', then there is no possible revival from the graveyard except in the most specific circumstances (Level Modulation), and even then, it must be properly summoned first. Lastly, if the monster has neither restriction, then it does not need to be summoned properly first, these cards can be discarded and Monster Reborn'd freely.
Almost all Synchro Monsters specify "One Tuner + one or more non-Tuner monsters" or similar. However XX-Saber Gottoms does not, as well as a Tuner, he just requires Earth monsters as components, these can be Earth attribute Tuners if you wish. Also, Red Nova Dragon has two tuners as a requirement.
Synchro Summoning involves sacrificing tuner monsters where normal summon, you can just summon the monster (level 4 or lower) or sacrificing non-tuner monsters on the field based on the monsters level. Level 5-6: 1 sacrifice Level 7+: 2 sacrifices (depending on the card)
A Synchro Summon is a special summon, so the summoned monster can be in attack or defence mode, just must be face up.
Generally, Synchro Summoning sends cards from the field to the Graveyard. There are some cards that allow you to use monsters in your hand as Synchro Material Monsters instead, such as Eccentric Boy.Eccentric BoyAttribute: WINDType: Spellcaster/Tuner/EffectLevel: 3ATK: 800DEF: 200When using this card as a Synchro Material Monster, the other Synchro Material Monsters is 1 monster in your hand. The Synchro Monster that used this card as a Synchro Material Monster cannot activate its effect, its effect(s) is negated, and is removed from play when removed from the field.
Synchro Monsters can be summoned from the Extra Deck (formally known as the Fusion Deck) by a Synchro Summon.A Synchro Summon can only be performed with one Tuner Monster and one or more face-up, non-Tuner monsters you control (with XX-Saber Gottoms as the exception, who can be Synchro Summoned with more than one Tuner Monster). You can tell if a monster is a Tuner by looking at the card type and seeing "/Tuner" next to it. For example, you can tell Junk Synchron is a Tuner since its card text shows "[Warrior/Tuner]".In order to Synchro Summon a Synchro Monster, the Levels of the monsters used must equal the Level of the Synchro Monster. For example, Gaia Knight - the Force of the Earth is a Level 6 Synchro Monster. That means Junk Synchron, a Level 3 monster, would need a monster(s) whose Level equals 3 to Synchro Summon that Synchro Monster (or any other Level 6 Synchro Monster for that matter). Once you have met the requirements, you can send the monsters from the field to the Graveyard and Synchro Summon the Synchro Monster (this still counts as a Special Summon).Just remember, unlike Gaia Knight - the Force of the Earth, who doesn't have any specific requirements besides a combined Level of 6, some other Synchro Monsters do. Some require specific Types, Attributes, Archetypes or monsters to be used.
If it was properly summoned by Synchro Summon, then yes, it can be brought back, assuming it has no other restrictions. That means if it got to the graveyard in any other way (ie, tried to Synchro Summon, but it was negated, or it was 'only' special summoned by Vayu, or was sent there by Gale Dogra), then it can't be reborn.
The Stardust Dragon can use its negation effect, but will not be able to resummon itself. Special summon-only monsters (which Synchro, Ritual and Fusion monsters are) must be 'properly' special summoned first (ie, Synchro, Ritual or Fusion Summoned) if you want to resummon them from the graveyard. There are cards that can get them on the field without properly summoning them, like Cyber Stein, and Starlight Road. If you summon them with these, the monster can't later be revived from the graveyard after it gets destroyed.