PEND BEST DEK LETS GOOOO!!!!!1!!!!
Metalfoes are a deck that relies on destroying ally cards to gain advantage, while also removing opponent's cards.
Metalfoes want to push the opponent into a war of attrition or a grind game, one that they will easily win due to how many cards they can pop.
Simply place 2 metalfoes in scale, summon bunch of guys, then fuse. The pend monsters effects, if you set a fusion spell with them, you can use it on the same turn, so you always have access to at least one fusion spell. If going second, fuse into Mithrilium, pop a card if you can, then fusion again into Azortless to pop yet another. If Azortless is destroyed, you have access to a pop whenever you destroy an allied card, so don't hesitate to pop Azortless to get that other pop. If going first, just summon Alkahest and set traps plus a parametalfoes fusion to get a strong interrupt plus an opportunity to fizzle a spell if Alkahest is targeted, and a 2500 beatstick during opponent's turn as long as Alkahest is alive. This probably won't come up much, but it's nice to have.
You can play links like Apollousa, or rank 9s like Jormungandr of HeartEarth due to Vanisher. When summoning off of counter, you always want to get a vanisher if possible. Because of this, you should generally not search Vanisher to keep good targets for Counter, and the summoning condition is quite costly nonetheless. I don't recommend Trap Trick because you can't search Combination, and you'll want to keep your copies of Counter. Waking the Dragon can be good if you find yourself losing your backrow too much.