You cannot return fusion monsters to the hand. Fusion and synchro monsters have to be returned to the extra deck.
Answer: If you are asking if you can use the fusion material monsters from your hand then yes if you are using the Polymerization card or Fusion Gate. But for other cards like Miracle Fusion or the Hex Sealed series they should be in the field.---------------------------------------------------------------------------------------------------------------You should never have a Fusion monster in your hand. Fusion monsters go in the Extra Deck, where they can be brought out at any time if you have the appropriate Fusion card and Fusion material monsters. If you are referring to if a Fusion monster is targeted by an effect that says "return **** monster to its owner's hand" then the Fusion monster is return back to the Extra Deck, not the hand. The same goes for Synchro monsters.
Destroyed or tributed Fusion Monsters go to the graveyard. They will return to the Extra Deck if something tries to return them to hand or deck.
Just like regular monsters, Fusion monsters will go to the Graveyard if they are destoyed. If a Fusion monster is supposed to "return to the owner's hand" or "return to the owner's deck" because of a card effect, it is returned to the Extra/ Fusion Deck.
if you have the necessary cards (fusion materials) in your hand to fusion summon yes, since fusion monsters have their own deck area.
No, the 'Neos' fusion monsters state how they must be summoned on their cards. The monsters must be returned from field to deck, you can't summon them like regular Fusion monsters using a fusion card and components in hand.
For Polymerization, the Fusion Components/ Fusion Material Monsters can either be in your hand or on the field, or a combination of both.
When it comes to using Fusion Monsters as Fusion Material Monsters, they are used no differently than any other monster you would use as a Fusion Material Monster.For example, in order to use Polymerization, the required Fusion Material Monsters must be present in your hand and/or field. Since Fusion Monsters cannot exist in your hand, if you needed to Fusion Summon Dragon Master Knight, you will need to have the Fusion Monster Blue-Eyes Ultimate Dragon on the field and Black Luster Solider in your hand or on the field.It should also be noted that some Fusion Monsters like Dragon Master Knight do not state that "a Fusion Summon of this monster can only be conducted with the above Fusion Material Monsters". So you can use Fusion Substitute Monsters like King of the Swamp in place of the Fusion Monster.
No, you cannot use Fusion Substitute Monsters for "Future Fusion". You can, however, use Fusion Substitute Monsters for "Chain Material" as long as those Fusion Substitute Monsters exist on your field or hand. The reason Fusion Substitute Monsters cannot be used from your deck is because they have no substitute ability while in the deck and thus cannot be used as replacements for other Fusion Material Monsters.
If you activate polymorization, then yes you may fuse monsters in your hand, or on the field. You must also have the correct fusion monster in your fusion deck.
Like Fusion and Synchro monsters, it will return to the Extra Deck. Any attached XYZ material will be placed in the graveyard.
"no.... there's a reason it says "from your hand or field" right in the card text. :)" Fusion Gate has no specification on it like that...
This all depends on the Fusion monster. If a Fusion monster like "Thousand Dragon" needs "Baby Dragon" and "Time Wizard", you activate "Polymerization" and send the monsters from your hand and/ or field to Fusion Summon "Thousand Dragon". There are cards called Fusion-Substitute Monsters monsters that can be used. They have written in their text: You can substitute this card for any 1 Fusion-Material Monster. When you do this, the other Fusion-Material Monster(s) must be the correct one(s).So in the case of "Thousand Dragon", you can use the Fusion-Substitute Monster "Versago the Destroyer" to take the place of "Baby Dragon" or "Time Wizard" when fusing. You cannot use two or more Fusion-Substitute Monsters in the same fusion as stated in the text. Some Fusion monsters have written in their text "A Fusion Summon of this Monster can only be conducted with the above Fusion Material Monsters." This means that you cannot use Fusion-Substitute Monsters in the fusion for the monster. Some Fusion monsters do not call for specific names of monsters to be fused. An example is "Chimeratech Overdragon". It's Fusion-Material Monsters are 1 "Cyber Dragon" + 1 or more Machine-Type monsters. Once you have the "Cyber Dragon", you can fuse any other Machine-Type monsters you have. A Fusion-Substitute Monster can be used instead of "Cyber Dragon", but the rest of the monsters must be Machine-Type.