The “Koa'ki Meiru” archetype revolves around Iron Core of Koa'ki Meiru; the vast majority of the monsters self-destruct during the End Phase unless you send the Spell Card to the Graveyard or reveal a certain type of card from your hand and some cards even require revealing or discarding it in order to activate their effects.
There are a lot of “Koa'ki Meiru” monsters and the ones featured in the Last Main Box, Gaia Genesis, are not even half.
The one that you see here is a “Pure Koa'ki Meiru Deck”, but these monsters are usually pretty versatile because of their powerful effects and their alternative maintenance costs.
Iron Core of Koa'ki Meiru is the main fuel for your strategies. Although it does nothing on it's own except recover itself, Iron Core of Koa'ki Meiru can be used to keep Koa'ki Meiru monsters on the field. Additionally Iron Core of Koa'ki Meiru is alro required to special summon your big boss monster Koa'ki Meiru Maximus. Because it is such an important card for this deck, there are multiple ways for you to repeatedly add it to your hand. If Iron Core of Koa'ki Meiru is in your graveyard, you can discard 1 Koa'ki Meiru monster or skip your draw phase to add it to your hand. Koa'ki Meiru Boulder can search Iron Core of Koa'ki Meiru from your deck when he is destroyed by battle, and Core Transport Unit can search it from your deck by discarding 1 card.
A monster with powerful stats and a destruction effect that destroys 1 card your opponent controls for free once per turn. Being easy to special summon combined with the fact that there is no limit to the number of Koa'ki Meiru Maximus you can summon per turn, this monster is great for OTKing with multiple copies. The downsides are that it's summoning condition requires you to banish a key card from your hand and Maximus himself is costly to maintain on the field. Meaning that you will most likely not be able to maintain more than one Maximus if you summon multiple. You can use Hey, Trunade! to return all set backrow to your opponent's hand and use your Maximus' effects to destroy their monsters for a game ending combo.
Since this deck has conditions for it's monsters to even stay on the field, it would make sense to use search cards to get the necessary conditions for your monsters to not self-destruct. Core Transport Unit searches your deck for Iron Core of Koa'ki Meiru for the cost of 1 hand card which helps you setup for Koa'ki Meiru Maximus or keep a Koa'ki Meiru monster alive on the field for 1 turn. Koa'ki Meiru Boulder searches your deck for Iron Core of Koa'ki Meiru or a Koa'ki Meiru monster. Searching for a monster can give you a monster to reveal during the end phase to maintain the Koa'ki Meiru monster on your field. Koa'ki Meiru Urknight can special summon a Koa'ki Meiru monster straight from your deck with no loss in advantage.
This deck could deplete your hand quickly with the retrieval effect of Iron Core of Koa'ki Meiru, Core Transport Unit's cost, and all the maintenance cost for all your monsters. Therefore some form of costless graveyard retrieval would be very welcome. Koa'ki Meiru Crusader retrieves a Koa'ki Meiru monster from your graveyard every time he destroys an opponent's monster by battle. If ever you do not need his retrieval effect, you can keep him in your hand to use as maintenance for Koa'ki Meiru Urknight with no loss in resources.
Koa'ki Meiru Sandman is a level 4 beater you want on the field for protection when you have other monsters, because of this the best way to bring him out is with Koa'ki Meiru Urknight so you would have something on the field to protect. When your opponent activates a Trap card, you can tribute Koa'ki Meiru Sandman on your field to negate that Trap card and destroy it. You can then summon another Koa'ki Meiru Sandman the next turn with Koa'ki Meiru Urknight. This is good to protect against popular trap cards like Treacherous Trap Hole, Wall of Disruption, Paleozoic Canadia, etc. To keep him on the field with no loss in resources, keep Koa'ki Meiru Boulder in your hand.
Last Gamble Can be used in your Main Phase, starting from the fifth turn. Upon activation, reduces your LP to 100 and discards 2 cards from your hand. You roll a die and draw that number of cards. This skill can only be used once per Duel.
Taking advantage of cards like Sphere Kuriboh and Treacherous Trap Hole, reaching the 5th Turn should not be a problem; at that point, the Skill will allow you, at the cost of two cards, to draw one to six new cards.
The deck focuses solely on quickly finishing off the opponent and the main Monster Card is really difficult to maintain on the field for multiple turns and easy to get rid of; if the OTK fails, there is going to be little to nothing to protect you during the opponent’s turn.
The deck is quite prone to bricking, which definitely doesn't help the fact that it really doesn't offer much compared to any other deck in the meta.
I generally do not tend to discuss matchups when it comes to decks that aren't exactly competitively viable (yet), but I will make an exception; “Koa'ki Meiru” is not a bad archetype, it was just randomly released inside a Main Box and it was not given enough tools.
Koa'ki Meiru Sandman can negate the activation of Trap Cards, of which Amazoness usually make large use or, but you need to tribute it in order to do so, so you'd obviously want to do it when you already have another monster on the field; Koa'ki Meiru Maximus can get around Amazoness Queen’s protection or just destroy Amazoness Swords Woman to avoid having to attack into it, but you are completely open during the opponent's turn and the Holy Guard variant can just banish your monsters freely without taking any damage.
Spellbook of Fate can banish your Boss Monster as soon as he hits the field and Silent Magician LV8 can even get over it naturally, so you are not free to destroy the Level 4 version with Maximus; in addition to this Silent Magician can negate a Spell Card per turn, which means that it can prevent you from recycling Iron Core.
Without Silent Magician, if you manage to get multiple monsters on the field with Koa'ki Meiru Urnight’s effect, the opponent will have trouble dealing with your monsters as they have naturally high ATK.
Mermail is definitely superior as an OTK Deck, so, if you go first, it's very likely that you are going to lose.
The Last Gamble Version, depending on the starting hand, may have a chance to survive and make a comeback.
Ddraw has that brutal 2k requirement. I would run it, but like you said it`s easy to play around it. Bandit seems like fun, perhaps I`m trying that.
What if you lose your Max¿ Only Ice could save you vs Fur Hire? One seems a little less for my taste, haha.
LC0 is easy, Espa Roba is the man. But wait are you willing to bait? I am curious now :D
Sandman is really good but the idea of tributing him to negate a trap usually disrupt my otk plan, with spiritualism or any one for one remover you will need him but with 3 hey trunade you will rarely need him.
I thought about the one max problem but the thing is I usually die before I summon another max as it's costy to summon and costy to maintain, playing with one max makes it harder to decide but lesser to brick
https://www.youtube.com/watch?v=37DF8eoBQBU I actually got to 10k DP in KC Cup with this Koa'Ki meiru deck, still i don't think its really a good deck but its pretty fun.
The reason I feel sandman is the best card in the koaki stuff right now is simply for his effect he is an awesome tech with awesome attack.
If I were to use him I’d run at one and summon on a turn I know I should be able to otk and make use of his effect for annoying traps
Sandman would be even better once we have Guardian and Wall as well.
Rock Stun meta in DL lol
With enough luck the Last Gamble OTK variant of this deck is... actually fairly decent. With bad luck however... yeah you're screwed. Neat deck though, and, the fact that you're fairly likely to get all the pieces of it while UR chasing for this box makes it fairly easy to build as well.
Has anyone come up with a Grass variant for the deck? Iron Core being recoverable from the Grave and Urgent Synthesis enabling plays out of the Grave (and restocking the deck) seems like it could open up some possibilities. Not to mention the in-archetype Mirror Force.