While using the skill "Three-Star Demotion", this deck is a lot less reliant on using it compared to the other versions. With multiple Rare Metalmorph, this lets you protect your monsters from a lot of targeted spells in the game, and using the skill will only let you summon Barrel Dragon faster.
This deck does not rely on using the skill repeatedly, and with only 1 Supremacy Berry, you will have to be more careful using the it. You can summon Barrel Dragon early if you are against someone that can potentially stop your summon. Safe chance to summon Barrel Dragon is first turn, or when you have a Rare Metalmorph. Setting the card at first turn will make it be untargetable by certain spells as well.
In certain cases, you might not want to summon Barrel Dragon right away, start with Sergeant Electro or Machine King Prototype to get a better understanding at your opponent's plays. If you manage to lock all the spell/trap card your opponent uses in that turn, you can summon Barrel Dragon and risk the 50% chance to destroy your opponent's monster, this can lead to a direct attack, or even the game right away.
Rare Metalmorph is the key card for surviving the early turns. Keeping it hidden as a surprise spell negate is an important factor to using it properly. This makes your opponent use their resource to try and take you down, but will only make yours stronger. It's better to use Enemy Controllers first to defend against attacks, and then use Rare Metalmorph to either destroy your opponent's attacking monster, or negate crucial targeted spell cards.