Welcome to Gaia! ::

Something fun to do. List a monster and the deck master ability you think it should have. Try to keep it within reason.

edit: and by reason I mean cost. All deckmasters have costs to their effects

Lava Golem:
While this card is in the deck master zone, once per turn subtract 500 attack points to inflict 500 life point damage to your opponent. Also, you may special summon this card to your opponents side of the field without tributing their monster. You still cannot normal or special summon monsters during the same turn you special summon this monster.

Man-Eater Bug while this card is in the deck master zone any time a monster you control is flipped summoned destroy one monster on the field

"I am pretty sure it cannot destroy cards from the deck master zone."

Magidog:
Once per duel, if a synchro monster is synchro summoned with a tuner monster that's the same type as the synchro monster, you can add one spell card from your graveyard to your hand.

no cost, but a limit, and fairly hard to pull off

Royal Swamp Eel
"Fish-Type Synchro Material Monsters are returned to the deck instead of sent to the graveyard."

Golden Flying Fish
"Tribute 1 Fish-Type Monster you control to send 1 card on the field to the graveyard."

Fishborg Blaster

"Discard 1 card from your deck. Special summon 1 Level 3 or lower WATER monster from your graveyard."

Big Core

"'B.E.S.' Monsters that have been Special Summoned may activate their effects as if they had been Normal Summoned."

Krebons

"Pay 800 Life Points to negate the attack of a monster your opponent controls."

Overdrive Teleporter

"Pay 2000 Life Points. Special Summon 2 Level 3 or Lower Psychic-Type Monsters from your deck."

Superancient Deepsea King Coelacanth

"You may discard a card to negate a card effect that targets 1 Fish-Type monster you control. You may discard a card to special summon four Fish-Type monsters from your graveyard. They cannot attack, their effects are negated, they cannot be tributed for a tribute summon, and they are destroyed during the end phase."

Neo-Parshath, the Sky Paladin

"The field is treated as 'The Sanctuary In The Sky' even if there is another Field Spell on the field. Once per turn, if you have fewer life points than your opponent, you may gain life points equal to half of the difference. You cannot attack or activate the effects of effect monsters the turn you activate this effect."

The Agent of Force - Mars

"Fairy-Type monsters you control are unaffected by spell cards as long as 'The Sanctuary In The Sky' is in play."

The Agent of Judgment - Saturn

"Once per turn, if 'The Sanctuary In The Sky' is in play and your opponent's life points are higher than yours, you may tribute 1 Fairy-Type monster you control to infict damage to your opponent equal to the ATK of the tributed monster. You cannot attack or activate spell or trap cards the turn this effect is activated."

The Splendid Venus

"If you control a 'Valhalla, Hall of the Fallen', cards you control cannot be negated."

The Calculator

"When one of your monsters battles a monster controlled by an opponent, increase the ATK of your monster by the combined levels of the attacking and defending monster x 100."

Red Dragon Archfiend

"As long as this card is in the Deck Master zone, neither player can set monsters, play monsters in defense position, or switch the battle position of monsters on the field."

Black Rose Dragon

"You may pay Life Points equal to the number of cards on the field x 500. If you do, destroy all cards on the field. This effect can be used by either player. If your opponent controls only Defense Position monsters, Plant-Type monsters you control can attack your opponent's life points directly."

Beast Warrior Beat down? >_>