How I would nerf this skill if I could:
Can be used if your Life Points are at 1000 or below, AND your Monster Zones are all empty.
Play 3 "Proto-Cyber Dragon" in Attack Position from inside your Deck to your side of the field. ("Proto-Cyber Dragon" in your hand or Graveyard will not be played.)
"Proto-Cyber Dragon" played with this Skill cannot be Tributed, and while they are face-up on the field, you cannot Special Summon except Fusion Summoning, nor attack except with Fusion Monsters.
You can only Fusion Summon once on the turn this skill is activated.
This skill can only be used once per Duel.
You forgot these lines:
- Battle damage your opponent takes from the fusion summoned monster becomes 0
- At the End Phase, send the fusion summoned monster to graveyard.
Should also make it so that you cannot activate spell and trap cards, except spell and trap cards whose effect involves fusion summoning a monster from the extra deck, during the turn you activate the skill.