An Underated deck, although there is no specific combo, this is what makes it interesting. So now let's read a guide about this Metalfoes deck
Article referenced & translated from: " Metalfoes Guide " by The Thingy & EEE on Master Duel Meta Page

Instructions for playing Metalfoes
Sections covered in this guide:
Introduce
Cool iron bodies meet burning metal machines and man/machine combine. Burn up the soul - Metalfoes Fusion!!
Metalfoes is a pendulum deck that mainly uses monsters in the Main deck to access useful Spells/Traps and FUSION SUMMON! So why should we play this deck? First you have to ask yourself, what is the best Deck to use Promethean Princess ? Yes, it is this deck (at this moment lol). And secondly, it's fun to play
Monster card
Most Metalfoes Monsters have the same Pendulum Effect: Once per turn: you can Destroy 1 face-up card on your field, then Set 1 Metalfoes Spell/Trap directly from the Deck to the field.
Coming to our first Effect Monster, it has an effect like when destroyed, you can add 1 Metalfoes Monster to your hand in EndPhase, it sounds slow and not very effective (and that's why there are so many ways to build deck but only use x1 of this card). However, this card can still help us have an extra piece of meat to use Fullmetalfoes Fusion which I will talk about later.
One of the strongest cards in the deck, when destroyed it will add 1 Metalfoes Monster from the extra deck to the hand but in return that added card will not be able to activate in the Pendulum Zone. However, we can still Normal/Special summon it, so it can be considered that we have more food to Pendulum/Fusion summon. In addition, this card is also level 7 so it can XYZ rank 7 with Metalfoes Volflame .
The only Metalfoes card that does not have a card set effect from the deck, instead it will destroy 2 face-up cards on your field to summon itself to the field, banish,... and has a few more effects that I almost never use so no need for qtam =)).
Normally we only need x1 of this card like Metalfoes Counter , because they are both relatively strong pieces for your endboard because the banish eff is quite ok.
Spell & Trap
You should only x1 this card because Mithrilium itself can be easily recycled.
YEP This is a Metalfoes card , maybe because there are so many mercenaries, sometimes you will forget this card also belongs to Metalfoes. This is the second best card in the deck, we can reuse it from the grave for free and still get +1. The Fusion effect is not One Per Turn , so it will be very useful at times
Because this card can return on its own, along with Mithrilium that can restore other Metalfoes cards, we will only need to x1 it in the deck to avoid bricking.
This card allows you to Fusion summon with a quick effect, so it is often used to fuse during the enemy's turn so that you can use the meat lump added by Raremetalfoes Bismugear as a material.
It is also used to deal with cards like Dark Rule No More, waiting and summoning Fullmetalfoes Alkahest.
Also one of the best cards in the deck and also a main searcher . There will be many ways for us to send this card to the grave and get a lot of resources (recommended to use Engine Magicians' Soul to get +4 cards, I will talk about this part later)
In addition, this card also has an effect in the grave, adding 1 metalfoes from extra so it may also be quite useful in the late game.
Extra deck
These are the two Fusion Normal monsters of the deck, although nothing special, BUT they become very strong because of Super Polymerization along with their summoning conditions. If you play Super Poly, I think you should put at least 1 of this card in your deck (Recommended is Crimsonite because it is better than the other cards in every aspect)
The second effect is a pretty good non-One per turn, helping to special summon Metalfoes. So we often summon 2 cards right in turn 1, the remaining card is to destroy the opponent's field.
We often use this card combined with Mithrillium to destroy the opp field, helping to overcome many difficult situations, so x1 is more than enough for this player.
- Great OTK ability to make all Metalfoes penetrate and still have x2 damage (BE Chaos max but more vip :v)
- The effect of destroying a card when leaving the field is very good with a few other cards (it is Promethean Princess that can destroy 1 more nx card)
That's right, this is also a Metalfoes card. Just kidding, this is one of the best cards ever printed and I bet you all know this. Banned in TCG, this card has an effect of Soft One Per Turn that adds a Pendulum card from deck to extra deck, and 1 SOFT ONCE PER TURN (very, very important) that destroys the card you are controlling (thereby activating a few effect of the Metalfoes monster) to add 1 Pendulum card from the Extra Deck to your hand.
For those who don't know this card, you will wonder why this card was banned, right? There are two main reasons, firstly, it can repeat the effect (loop) many times (It can repeat up to 5 times in 1 turn in this deck), and secondly, when paired with Astrograph Sorcerer , it helps We have a lot of resources and a huge amount of advantages. So there is no reason for us not to play this card.
Main deck Engine/Extender
Astrograph Sorcerer and Magicians' Soul will be the two most important Engines, the rest is up to your preference and reference.
Both cards Illusion of Chaos and Preparation of Rites have the same purpose, which is to search for Magicians' Souls. As for why Magicians' Souls is so necessary, it is because it has the ability to send up to 2 Metalfoes Combinations to the grave, thereby bringing a +4 cards advantage. So it's very cool!
This engine is so crazy =)), it helps us have Beyone the Pendulum and Electrumite before Pendulum summons, even in the build mix with Yang Zing, it also helps us add Oracle of Zefra to play Engine Zefra.
Tech card




































































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