You can target 1 other card you control; destroy it, and if you do, add 1 "roid" card from your Deck to your hand. During damage calculation, if your "roid" monster battles: You can send 1 "roid" monster from your Deck to the GY; switch the original ATK and DEF of your battling monster during the damage calculation only. You can only use each effect of "Megaroid City" once per turn. You cannot Special Summon monsters from the Extra Deck, except Fusion Monsters, the turn you activate either of this card's effects (even if this card leaves the field).
How to Get
Searches any Roid card.
Can change the attack and defense of Roid monsters.
Searches and sends a Roid monster from your deck to the graveyard.
Requires you to destroy 1 card on the field to search.
Extra deck mechanics are restricted to Fusion summon when you activate Megaroid City.
You can search out extra copies of Megaroid City in case your opponent destroys your current copy.
You can search out monsters to use as fusion materials for your Roid fusion monsters.
Switch Attack and Defense
Here are Roid monsters with stronger defense than their attack which you can switch around with Megaroid City. Switching the attack and defense of Truckroid so that he will be strong enough to destroy his first monster, from there he will easily be able to destroy additional monsters to gain even more attack.
Expressroid can be used to recovery the cards you destroyed as cost for the search effect or Roid monsters you milled from deck to the graveyard, making him excellent for gaining resources.
Aside from monsters, you can use Megaroid City to search out support Spell and Traps with "roid" in their name. Vehicroid Connection Zone is a fusion spell card that makes the fusion summoned monster immune to destruction and effect negation. Emergeroid Call negates any effect activation and gets rid of extra copies of the negated card from your opponent's deck.
Destroy wondergarage, search any, with wondergarage effect special mixeroid, tribute him special summon any roid, poly them bring
pair cycroid i dunno, if you survive one turn, destroy pair cycroid with this bring the dude with 5000 def and wait for your opponent activates a trap holes. and done, your roid still a crap archetype like always.