I was in the mood to make weird cards

[Toffee.]

Harmonic Mutation
Spell
Pay 1000 Life Points. Target 1 Synchro monster you control: Xyz Summon 1 Xyz monster from your Extra Deck who's name contains the Target monster's name, using this card and the Target monster as Xyz Materials. Then, you can Banish this card from the Graveyard: Until the End Phase of this turn, the Summoned monster is unaffected by the effects of your Opponent's cards. You cannot conduct your Battle Phase the turn this card was Banished by it's own effect.

Cross-Dimension Shifting
Spell
Target 1 Rank 4 Xyz monster with a Tuner monster attached to it as an Xyz Material. Banish both the Target monster and it's Xyz Material(s), and if you do, Special Summon 1 Level 8 Synchro monster from your Extra Deck. You cannot conduct your Battle Phase the turn you activated this effect, and you cannot Special Summon for the rest of the turn.

Wonder Polymer
Spell
Discard 2 "Polymerization". Special Summon 1 Xyz monster from your Extra Deck, who's Rank is equal to the number of monsters in your Graveyard. Then, you can attach 2 Fusion Monsters from your Extra Deck, with the appropriate Level listed on the Summoned monster, to the Summoned monster. The Summoned monster cannot activate it's effects or declare an attack, during the turn it was Summoned. You can only activate 1 "Wonder Polymer" per turn.

Rustbound Scrap Dragon
EARTH / Rank 8
[Dragon/Xyz/Effect]
Must be Xyz Summoned by the effect of "Harmonic Mutation" and cannot be Summoned by other ways. Once per turn, you can Detach 1 Xyz Material from this card and Target 2 cards on the field. Destroy them. If this effect resolves, and the Opponent has no monsters on his/her side of the field, this card cannot declare a direct attack this turn. If this card is destroyed by your Opponent's card(either by battle or card effect), Target 1 "Scrap" monster in your Graveyard: Special Summon it in Face-up Defense Position. The Summoned monster is Banished when it is removed from the field.
ATK 3300 / DEF 2500

Phantom Stardust Dragon
WIND / Rank 8
[Dragon/Xyz/Effect]
Must be Xyz Summoned by the effect of "Harmonic Mutation" and cannot be Summoned by other ways. Once per turn, during either player's turn, you can detach 1 Xyz Material from this card: Until the End Phase of this turn, all Face-up cards you currently control cannot be destroyed OR affected by Opponent's cards. Then, all Face-up monsters you currently control loose 800 ATK and DEF until the End Phase.
ATK 3000 / DEF 2500

Burning Armory Arm
LIGHT / Rank 4
[Machine/Xyz/Effect]
Must be Xyz Summoned by the effect of "Harmonic Mutation" and cannot be Summoned by other ways. Once per turn, you can Detach 2 Xyz Materials from this card and Target 1 Face-up monster on the field: Equip this card to the Target. While equipped by this effect, double that Target's origional ATK. If the Target monster battles an Opponent's monster: Inflict piercing damage. When that target destroys a monster by battle and sends it to the Graveyard: Inflict damage to your opponent equal to half the ATK of the destroyed monster in the Graveyard.
ATK 2300 / DEF 1700

Iron-Fist Colossal Fighter
DARK / Rank 8
[Warrior/Xyz/Effect]
Must be Xyz Summoned by the effect of "Harmonic Mutation" and cannot be Summoned by other ways. Once per turn, during either player's turn, you can Detach 1 Xyz Material from this card: This card gains 100 ATK for each monster in any Graveyard, until the End Phase. If this card is destroyed as a result of battle, Target 1 monster in either player's Graveyard: Special Summon that Target. Banish it when it leaves the field.
ATK 3300 / DEF 1500