You can Tribute 1 Machine monster; Special Summon 1 non-WIND "roid" monster from your Deck. You can pay half your LP and banish any number of Machine monsters from your GY, including this card; Special Summon from your Extra Deck, 1 "roid" Fusion Monster with the same Level as the number of those banished monsters, ignoring its Summoning conditions, but destroy it during the End Phase. You can only use each effect of "Mixeroid" once per turn.
How to Get
Can special summon Roid monsters from your deck.
Good defense stat.
Allows you to special summon a Roid fusion monster from the extra deck.
Must pay half LP to special summon fusion monster.
Special summoned fusion monster is destroyed during the end phase.
You can special summon these Roid monsters with Mixeroid’s first effect. Expressroid allows you to retrieve 2 Roid monsters from your graveyard. And UFOroid allows you to special summon Machine-type monsters from your deck when he is destroyed by battle.
You can create a 30 card deck and use That Grass Looks Greener to load your graveyard with Machine-type monsters and Mixerroid. You can use Needlebug Nest to send the top 5 cards of your deck to the graveyard, hopefully milling some Machine-type monsters to the graveyard. Magical Merchant could also help mill some Machine-type monsters to the graveyard while adding a spell/trap card to your hand.
You can use Machine Duplication on Mixeroid to special summon up to 2 more from your deck, swarming your field with high defense monsters that could special summon from your extra deck when they are in your graveyard.
Switch Attack and Defense
Since this monster has weak attack stat but a significantly high defense stat, you can use cards that exchange both to give this monster an attack boost so that it overpower enemy monsters.