The goal of the deck is to summon Blue-Eyes Ultimate Dragon by activating the effect of Cyber-Stein. Here are ways to summon two of the Dragon.
1st Ultimate Dragon summon (Using Magical Hats)
Set a monster and Magical Hats.
Activate Magical Hats during your opponent's battle phase. Choose "7" or Magic Formula.
You will gain life points due to the effect of "7" or Magic Formula when those cards are sent to the graveyard.
Now your life points are more than 5000 (5400 or 5700): activate the effect of Cyber-Stein, then special summon Blue-Eyes Ultimate Dragon.
2nd Ultimate Dragon summon (Using the effect of Cyber-Stein)
You have less than 1000 life points due to the effect of Cyber-Stein, then activate the "Life Cost 0" skill.
Now you can use the Cyber-Stein's skill without paying life points because of the skill.
Finally 2nd Blue-Eyes Ultimate Dragon is on your side of the field.
The combination of Tea's skill, Life Cost 0, and two Blue-Eyes Ultimate Dragon special summons by Cyber-Stein's effect is very powerful.
Starter life points is 4000 and not enough to activate the effect of Cyber-Stein.
You will lose an opportunity to use Cyber-Stein if you get damaged.
One of the Tea's skill, Life Cost 0, allows you to activate Cyber-Stain's effect and summon Blue-Eyes Ultimate Dragon without life points for cost.
How to get
[Life Cost 0] You can use the skill when your Life Points are 1000 or less. You do not have to spend Life Points to activate a card until your opponent's next turn ends. You can only use the skill once per Duel.
Is that bugged ?
I just set Des Wombat, and when I played Cyber-Stein There was no possobility to activate the effect. Not on it's on, and not chosen by me, too.
I had Blue Ultimate dragon in Extradeck ...
Here's a pretty good example of how to use this deck
Alot of people seem to think its best to use a skill that increases starting LP is best for this deck. Thats completely wrong. Life cost 0 is best since even if you get below 5k LP you still have a chance to use his skill