The deck is designed to disrupt your opponent while making full use of the effects of Lair of Darkness. Though this deck does not specifically rely on Lair of Darkness, this deck plays on the fact, many decks do not currently plan for defence against Mirror Force cards.
PLEASE NOTE: This deck is a fun deck which helps revive the use of Mirror Force in a somewhat fun and odd way. This deck is for casual use only and is not for use in competition. This deck has no defined win condition but aims to win by disrupting your opponent and slowly killing with fusion dragons.
This deck contains multiple different mirror force cards and was originally made as a joke deck using the old mirror force cards. However, in testing this deck has done surprisingly well in local tournaments and it is very much a troll and almost meme like deck. Below is some information on key cards to help people who are interested in playing this deck. (This deck is also a cheap budget deck)
Lair of Darkness
This card will be referred to as LoD for the remainder of this article.
LoD is a field spell released in the structure deck: LoD. This card has a variety of effects, the first effect of this card is that it changes all monsters on the field into Dark Monsters. This synergises with the card's second effect, you can use one of your opponents monsters for the tribute of a dark monster to activate one of your card effects. Though this can only be used once per turn, this is useful for removing your opponents monsters for the effects of traps such as Crush Card Virus, which otherwise might have been difficult to remove. Not only this, the LoD also adds tokens to the turn players side of the field during the end phase up to the number of monsters tributed during that turn. This helps you build up targets for other virus cards and can synergise well with cards such as Gozen Match. Though this card has a lot of useful effects, it should also be noted that LoD must activate at the end of every turn whether monsters were tributed or not, this makes the card highly susceptible to Ghost Ogre which means this card does not currently see a lot of play in meta.
Mirror Force Launcher
Generally with this card you will want to leave this card set for the cards second effect, however the first effect of this card can also be useful. It should probably first be noted that Mirror Force Launcher can only search for the original Mirror Force and can not be used to search for cards such as Storming Mirror Force, however as we are running The Fang of Critias, then this can assist with bringing forth the Mirror Force Dragon. The set effect of this card means that if your opponent was to destroy the card with something like twin twister or heavy storm duster (which are both common plays against virus' on LoD decks), your opponent lets you set a mirror force from your hand/deck/GY as well as setting itself again from your GY. This both helps setup for Fang of Critias and provide protection on what can often be an empty field in this deck.
The Fang of Critias
For those who have watched the original Dual Monsters series, you are probably familiar with this card as one of Kaiba's cards during the arc following battle city tournament. Of course in the anime this card was somewhat more consistent and more powerful, however it is nice to know that the card has perfect synergy with this deck as well as providing some powerful monsters to your field. This card can be used with Ring of Destruction, Mirror Force, Crush Card Virus and Tyrant Wings to make fusion versions of the legendary dragon. More information on the fusion monsters to follow.
Mirror Force Dragon
Probably the most powerful card in this deck, Mirror Force Dragon is not only a monster, but basically a powered up version of the original Mirror Force card used in its creation. Mirror Force Dragon does not only destroy your opponents monsters when it is attacked, Mirror Force Dragon also destroys every card your opponent controls including spells/traps. But it doesn't stop there, Mirror Force Dragon does not have to be attacked for this effect to take place, but will happen when your opponent targets any of your monsters with an attack OR card effect while it is on the field.
Doom Virus Dragon
This card is actually an interesting fusion card of The Fang of Critias and Crush Card Virus, though a while ago Crush Card Virus got errata'd, Doom Virus Dragon maintains the original effect of the first Crush Card but without the monster tribute. Firstly on summon this card will destroy all monsters your opponent controls which have 1500atk or higher on the field or in hand (hand is revealed). Then for the next 3 turns your opponent draws a card, they must reveal the card and send any monsters with 1500atk or more to the GY which can really limit your opponents plays. This makes it harder for your opponent to be able to kill this 1900atk monster.
Destruction Dragon
This is the newest monster in the legendary dragon series. Destruction dragons effects are actually more powerful than they first appear and it has a nice 3000def points to help make it harder to remove. So what is it that makes this card powerful you ask? Unlike ring of destruction which is used in this monsters creation, you can destroy 1 card your opponent controls per turn and if this is a monster, deal the monsters original attack directly to your opponents life points, you do not take any damage from this effect so this is almost like an upgraded form of Ring of Destruction with Ring of Defense built in and can be used multiple times. However, a commonly missed feature of this monster is that it can destroy ANY card on the field. Though you don't do any damage to your opponent if the card you destroy is not a monster, this can be very useful for clearing your opponents restrictive spells/traps.
Lilith, Lady of Lament
I'm not going to go through all the LoD cards, however for new players, this card requires a mention. Lilith is a 3* monster with 2000atk, however on Normal summon it will halve its attack to 1000atk. However, Lilith is a monster with a very interesting quick effect. By tributing 1 Dark Monster you can select 3 normal traps from your deck and your opponent must choose 1 to be set onto the field. Your opponent selects this trap randomly and they do not get to see which card was set, however if you select 3 of the same trap your opponent will know what card it is. Lilith is useful in the LoD archetype but is also very useful for setting up traps to be used with Fang of Critias. The most dangerous thing about Lilith is that its effect is a Quick Effect which when combined with LoD means that it can tribute your opponents monster to gain a trap during both your turn and your opponents turn. It also can tribute itself when needed.
Spirit Reaper
Odd card for 2019 and I daresay a lot of people have not seen this card since about 2007, so why use this here? I often get asked this question and I can only really show its usefulness in a duel, but there are quite a few reasons to use Spirit Reaper. Spirit Reaper is a monster which can not be destroyed by battle or card effect making it a useful stall tactic, however it will destroy itself if the monster is targeted in any way, whether this is by a monster or card effect and also if you try to equip the monster with an equip spell. Although this seems risky, it is somewhat essential to note that the number of "target" effects have decreased in a lot of more modern decks, that isn't to say they are gone entirely, but you can often sit a couple of turns with the monster as a protector of your LP. However, what if this monster is targetted? Well oddly with this deck, that's not entirely the end of the world. According to Spirit Reapers effect, it will only destroy itself after the targeting has resolved, this means we still have the monster throughout the length of the chain. Spirit Reaper is a monster with low attack and a dark monster meaning that you can chain Crush Card Virus to a targeting effect and not only will your opponents effect miss its target as it is tributed for cost, but they will also lose all monster with 1500atk in both hand and on field (However this is best to avoid where possible with some decks as the opponent will also get the option to send up to 3 monsters from their deck to GY with 1500 or more attack which against some decks can give a big disadvantage).
WEAKNESSES
This deck has a lot of weaknesses against the current meta and would probably have been stronger many years ago, however this does not mean the deck does not do reasonably well in casual play and in local tournaments. As the category suggests this is more of a casual fun deck, the decks main weaknesses are with trap negation and decks with large numbers of spell/trap removals which can often result in your hand falling empty. The deck also works on mainly disrupting your opponents plays, so other than Diabolos and the Dragons, there is no real set win condition.
OTHER INFORMATION
This deck has a lot of room for variation and can even be used in conjuction with cards such as Raging Tempest (As you have field removal and you can make monsters from spells/traps)
Please remember again, this is a fun deck, however this deck is only really for casual and local play, feel free to use this as a template for other decks or as a budget deck as the parts of this deck are all cheap and mainly from structure decks.