Cannot be Normal Summoned or Set. Must first be Special Summoned with "Rise of the Snake Deity" and cannot be Special Summoned by other ways except by its own effect. This card gains 500 ATK for each Reptile-Type monster in your Graveyard. This card cannot be targeted by, and is unaffected by, Spell/Trap effects and other Effect Monsters' effects. When this card is destroyed by battle and sent to the Graveyard: You can banish 1 other Reptile-Type monster from your Graveyard; Special Summon this card. When this card inflicts Battle Damage to your opponent: Place 1 Hyper-Venom Counter on it. When 3 Hyper-Venom Counters are on this card, you win the Duel.
Stats and revival effect depend on the number of Reptiles in your graveyard.
Rise of the Snake Deity
To activate Rise of the Snake Deity you need a face-up Venominon, the King of Poisonous Snakes to be destroyed via card effect. You can activate cards like Destruct Potion to destroy Venominon yourself.
You can revive Venominon in your graveyard with Viper’s Rebirth. That Venominon will be destroyed during the End Phase so you can then activate Rise of the Snake Deity.
Vennominaga’s power largely relies on the number of Reptile monsters in your graveyard. The best option for loading your graveyard would be Snake Rain. This can also be used to put Venominon in your graveyard for reviving with Viper’s Rebirth or Limit Reverse. Use Future Fusion to dump all your Reptile-type Worm monsters into the graveyard.
It really just depends on the popularity of the character and if they can find a purpose for them. That being said, I don't see a character like Valon or Misty happening. They're not popular enough, and they don't really have a good enough gimmick for a skill or the like to make them work. Though it's worth pointing out that Misty probably does technically have enough of a cardpool to work with.
There’s two reptilianne, Naga & Lamia left plus they can add generic EB immortal support or reptile support with her. Adding her wouldn’t make the most exciting event but they can just use her to fill in the support cards for the immortals while the other sale signed get their respective archetypes.
It's pretty easy to play around Yubel. But if an opponent somehow manages to summon this card (which is pretty unlikely to be honest), you're in bib trouble if you don't have Lava Golem or ATK boosting cards.