This is a pretty straightforward Deck that focuses on Summoning high Level monsters like Beast King Barbaros and Fusilier Dragon, the Dual-Mode Beast without Tributing, and then utilizing cards like Forbidden Chalice and World Legacy Clash in order to ripristinate their original ATK. Not exactly a competitive Deck, but it can definitely catch people off guard.
Beast King Barbaros is a Level 8 monster that can be Normal Summoned/Set without Tributing, but, if it is, its original ATK becomes 1900. Now, even if it was Normal Summoned/Set without Tributing, Beast King Barbaros remains a Level 8 monster, which means it still has access to Beatdown, making it a 2200 ATK monster on your turn by itself, which is quite decent.
If you activate World Legacy Clash, banishing Beast King Barbaros, the Quick-Play Spell will lower the ATK of the opponent’s monster you targeted by 3000, even if the original ATK of your monster on the field was 1900, and, during the End Phase, when Barbaros is returned to your side of the field, it will have 3000 ATK.
Fusilier Dragon is a Level 7 monster that, just like Beast King Barbaros (and Charging Gaia the Fierce Knight), can be Normal Summoned/Set without Tributing, but, if it is, its original ATK and DEF are halved.
You can use World Legacy Clash to greatly decrease the ATK and DEF of an opponent’s monster, and, during the End Phase, have Fusilier Dragon return to your side of the field with 2800 ATK and 2000 DEF, or you could use Forbidden Chalice. If you target Fusilier Dragon with Forbidden Chalice, it's original ATK and DEF will revert to 2800 and 2000 respectively, and, even after the effect of the Quick-Play Spell has worn off, the ATK and DEF of your monster will stay the same.
You can also use Forbidden Chalice to temporarily negate the effect of an opponent’s monster like Legendary Six Samurai - Shi En, allowing you to activate and resolve the effect of Treacherous Trap Hole.
Beatdown allows Barbaros to reach up to 3300 ATK by itself, which would put it above Cosmo Brain and Revendread Executor. Running so many high-Level monsters that are also easy to Summon gives this Skill a lot more value.
This Skill can be used to guarantee a Monster, a Spell, and a Trap Card in your opening hand, which would admittedly fix one of the main issues you are probably going to face when playing this Deck: consistency. Starting the Duel with Barbaros (or Fusilier Dragon), World Legacy Clash (or Forbidden Chalice), and something to protect your monsters is the ideal scenario.