One of my favourite ways to win in this game is to defeat people with uncompetitive decks that take you by surprise. Burn damage is one of those ways to do it and make people rage quit. Testing out this second one, it is more overpowered than the last one not documented on UNGROOVYGORDS (Yet).

Monsters:
Marshmallon X2
Helpoamer
Aroma Jar X3
Dice Jar
Morphing Jar
Secret Sect Druid
Stealth Bird
Self=Destruct Ant
Eater Of Millions
Cyber-Stien
(13)
Traps
Skill Drain
Wall Of Revealing Light
Starlight Road
Burning Mirror Force X3
Witch’s Strike
Evenly Matched
Coffin Seller
Red-Reboot
Nightmare Wheel X3
Meta-Verse
(14)
Spells
Harpie’s Feather Duster
Monster Reborn
Raigekai
Dark Sanctuary
Messenger Of Peace
Terraforming
Mystic Mine
Moon Mirror Shield
Cauldron Of The Old Man X3
Instant Fusion
(12)
(40)
Extra
Fusion
Thousand-Eyes Restrict
Time Wizard
Cyber End Dragon X3
Naturia Exerio X6
(8)
Link
Relinquished Anima
Knightmare Ceribus X2
Knightmare Phenix X2
Topologic Bomer Dragon
(6)
Synchro
Stardust Dragon
(1)
(15)
Combos
There are no main cards due to all of them being either burn damage, lockdown and overall defensive. Then Cyber Stien, Instant Fusion monsters, Moon Mirror Shield are the ideal offensive cards. Extra are the limited Feather Duster and Raigekai or Knightmare link monster effects.
Risk cards include Cyber Stien and Dice Jar with one summoning a strong monster for the one-turn kill, negate most cards and then Dice Jar is capable of dealing 6000 damage or less. Combo with Cauldron Of The Old Man to regain life points. Than Instant Fusion to summon the ultimate Time Magician or Thousand Eyes Restrict.
Lockdown cards include Mystic Mine, Messenger Of Peace, Skill Drain, and Naturia Exertio if lots of cards are in the graveyard.
Drawing Cards Include Morphing Jar, Metaverse, Terraforming, Red Re-Boot
Defensive cards include Moon Mirror Shield, Dark Sanctuary, Starlight Road, Evenly Match, Witch’s Stike, Wall Of Revealing Light, Stardust Dragon, Nightmare Wheel