In the first few turns, try to get some draws using Kotetsu if you get it in your starting hand. If Yugi gets first turn and sets a monster, then Kotetsu will not work. But you can take a few attacks before summoning Labyrinth so that you have more turns to try and draw for Riryoku Field.
Once you have Labyrinth, equip him with Gravity Axe - Grarl to prevent Yugi's flip monster effects.
If you already equip your Labyrinth with Gravity Axe, don't set your Kotetsu anymore since Yugi will most likely not attack it, unless he has a face up attack position monster on the field.
Yugi only has 2 Order to Charge, so you only ever need to set 2 riryoku field. It's recommended that you set them one at a time so that you don't clog your spell/trap zone. Sometimes Yugi also clogs his own field, preventing him from using his OtC.
Use Abyssal Designator 1 turn before your last. This is so you don't force Yugi to throw his Sphere Kuriboh from his deck in case his cards left is lower than yours. It's also so that you get comeback bonus.
Get your LP to 500 or below. Adjust your LP by letting Yugi attack you directly, placing your monsters in attack position to let Yugi attack them, or paying for the effect of Power Injector or Mirror Wall.
Use Wall of Disruption, Mirror Wall, or Enemy Controller to save yourself from lethal attacks.
Next you need Breath of Light to clear Yugi's field. Do not summon Cerberus before activating Breath of Light if Yugi has a set spell/trap card, that card might be Order to Charge.
After clearing Yugi's field, activate Ojama Overflow to fill his monster zones with Ojama tokens which cannot be tributed. At this point you can stall easy for the rest of the Duel.
Summon Mythical Beast Cerberus and another monster while stalling and them keep on the field. Do not attack.
What you need for your final turn are: 1 Gravekeeper's Vassal, 2 Union Attack, 1 Exchange, 1 Enemy Controller, and 1 Mythical Beast Cerberus and 1 other monster on the field before your final turn. You can use extra Enemy Controllers you have to power up Mythical Beast Cerberus, do not use Enemy Controller's second effect.
On your final turn, summon Gravekeeper's Vassal then use 2 Union attacks on him.
Use Enemy Controller to switch an Ojama token to attack position.
Use Exchange to take Yugi's Sphere Kuriboh if he has it on hand. Make sure you have nothing important in your own hand when you activate exchange.
With you boosted Gravekeeper's Vassal, attack the attack position token to finish the Duel.
Exactly the idea for the reason life cost 0 is not most necessary. I used alpha for a reason because I used Rex Raptor as the farm character, whose decent skill I have is only alpha. You may use other skills like restart or life cost 0. That's totally better. I just wanna show that you can farm even without any skills, while without compromising much of the win rates.
This deck works very well
- Gravity Axe will lock down Yugi's defense position monster
- Horn of The Unicorn so Valkyrion cannot get over Labyrinth Wall's defense
- Labyrinth Wall + Shield & Sword + Unicorn + double Gravity Axe = 4700 ATK, enough to bring Vassal's ATK into over 10000. Just make sure you activate Shield & Sword first, then summon Vassal, use Secret Pass and Union Attack before you equip the second Axe to Labyrinth Wall
- You don't need to bring AMA, because Yugi won't activate Order to Charge on your last turn