Approximately 20
how to make a bad deck: use many high level monsters that can't be special summoned. don't use an extra deck. use many normal monsters. use a 60 card deck. don't use cards that cost more than $0.50 dont ever use cards that destroy other monsters/spells/traps
You may have a total of 15 fusion and synchro monsters in your extra deck(renamed from fusion deck with the addition of synchro monsters)
Ritual monsters, and the rituals for them are in your regular deck.
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.
You can have up to 15 synchro's or fussion monsters total in your extra deck.
Synchro Monsters are placed in the Extra Deck along with the Fusion Monsters at the beginning of a Duel.
add some more powerful monsters. It doesnt have many strong monsters so add some. the deck comes with so many monsters you could tribute so add some really strong cards
up to 20 and the rest are magic and trap cards
A chaos deck is a deck that runs mainly light and darkness monsters where the light monsters are not lightsworn monsters. The focus of this deck is summon the chaos monsters(Black Luster Soldier-Envoy of the Beginning, Chaos Emperor Dragon-Envoy of the End, Chaos Sorcerer, and Dark magician of Chaos) while preparing to summon the chaos monsters this type of deck is also removing from play the opponent's monsters from play. This deck gets its name from not only from the monsters but also the booster pack in which this card were first released; Invasion of chaos. This deck works wonder with Dark Armed Dragon.
No, there is no rule that says you must have any monsters at all in your deck. You can make it 100% Spell and Trap cards if you wish.
It is currently now called the "Extra Deck", and a maximum of 15 cards (Fusion, Synchro, Xyz Monsters) are allowed.
No, you cannot use Monster Reincarnation to add a Synchro Monster from your Graveyard to your Extra Deck. Monster Reincarnation allows you to return a monster from your Graveyard to your hand, but it does not specifically allow for the retrieval of Synchro Monsters to the Extra Deck. Synchro Monsters can only be Special Summoned from the Extra Deck under specific conditions, not returned to it from the Graveyard.