The artwork of "Myutant M-05"
The "Myutant" monsters seem to base their designs around the motif of captured alien organisms being kept in a biological laboratory (as shown in "Myutant Evolution Lab"). The lower-Level Main Deck WATER Psychic "Myutant" monsters are depicted as such with their names indicating their specimen number, whilst the higher-Level ones are the result of these monsters merging with other things, giving some members like "Myutant Beast" a chimeric appearance and "Myutant Arsenal" a possessed machine whereas "Myutant Mist" appears to be an assortment of minerals and flora; meanwhile, "Myutant Synthesis" and "Myutant Ultimus" take on hydra-like appearances using a combination of "Beast" and "Mist".
The "Myutant" archetype has a banish and Special Summon focused play-style, with the higher Level Main Deck members having protection against various card types: "Beast", "Arsenal", and "Mist" cannot be targeted by monster, Spell, and Trap Cards, respectively. They also cannot be Special Summoned through means other than a "Myutant" card, though this is by no means an issue as the archetype has access to both "Myutant M-05" and "Myutant ST-46", both of which are key cards that upon being Normal or Special Summoned,allow you to add either a "Myutant" monster or Spell/Trap, respectively. These two can also Tribute themselves and banish a card from your hand or face-up field to Special Summon their brethren from the hand or Deck based off the card you banished for part of the cost for their effects. "Myutant GB-88" can be Summoned from the hand during your opponent's Main Phase, provided the Field Spell "Myutant Evolution Lab" in your Field Zone, and upon doing so allows you to Tribute itself and banish a card to Summon a Level 8 "Myutant" that is banished or in the GY. The Extra Deck members are the Fusion Monsters "Synthesis" and "Ultimus"; "Synthesis" requires members with two different Attributes to be Fusion Summoned and upon being Fusion Summoned can target and destroy 1 card on the field. It can also make itself immune to any effects of the same type as a card they activate though if it meets its end, it can add back 1 of your banished "Myutant" cards. "Ultimus" on the other hand requires 3 Level 8 or higher "Myutant" monsters and is able to put a stop to your opponent's plays by banishing a "Myutant" of the same card type as the one they activate and banished the card, thus preventing them from gaining advantage off of its destruction. If it is destroyed after being Fusion Summoned, it allows you to add back 3 of your banished "Myutant" cards, though only 1 of each type (Monster, Spell, and Trap).
For the Spell/Trap Cards, there is the Field Spell "Myutant Evolution Lab" that allows you to immediately Special Summon a Level 4 or lower "Myutant" monster that is banished or from the hand which can in turn trigger the effects of "M-05" and "ST-46". Not only that, but it increases the ATK of your "Myutant" monsters by 100 for each banished "Myutant" card with a different name while also allowing you to place a "Myutant" from your hand on the bottom of your Deck and then draw 1 card. "Myutant Blast" is an Equip Spell that can be only be equipped to the higher Level members and allows you to immediately banish an opponent's Special Summon monster when yours attacks. "Blast" can also banish itself to send the equipped monster to the GY and Special Summon a different Level 8 "Myutant" from your hand or Deck. "Myutant Fusion" is able to Fusion Summon one of your boss monsters by banishing the materials from your hand or field, but if your opponent has activated a card or effect during your turn can use materials from the Deck and GY instead. "Myutant Cry" is a Normal Trap that also Fusion Summons during the Main Phase, but instead uses monsters from the GY and that are banished by shuffling them into the Deck. This allows easy recycling of your used monsters on top of potentially disrupting anything your opponent may attaempt.
Important cards to consider are ones such as "Emergency Teleport", as it can kickstart your turns and plays, and "Trade-In" can make easy use of your Level 8 monsters to draw 2 cards. "Leviair the Sea Dragon" is also a good choice as it can trigger the effects of "M-05" and "ST-46" easily, and mixing in "PSY-Framelord Omega" can help with recovering your used Spells/Traps for a card like "Pot of Avarice".