Horrot-King of Destruction

[Beerus]

 

Cannot be Normal Summoned/Set. When an Effect Monster you control is destroyed by battle and sent to the Graveyard: You can Special Summon this card from your hand. Once per turn: You can target 1 Level 6 or lower Effect Monster in your Graveyard; equip that target to this card. (You can only equip 1 monster at a time to this card with this effect.) This card gains ATK equal tothe Level of the equipped monster x 100. When this card destroys a monster by battle and sends it to the Graveyard: You can banish 1 equipped monster; inflict damage to your opponent equal to half the original ATK of the monster banished by this effect.

[Nightmare Stomper]

You have some syntax issues, and some basic playability problem. Also, the card design is bad in that its effect MUST be activated. Also, including Xyz monsters is a bit overkill. Try this :P

 

Cannot be Normal Summoned/Set. You can Special Summon this card (from your hand) when an Effect Monster you control is destroyed by battle and sent to the Graveyard. Once per turn, you can Target 1 Level 6 or lower Effect Monster in your Graveyard: equip that target to this card (Max. 1). This card gains 100 ATK x the Level of the equipped monster. When this card destroys a monster by battle and sends it to the Graveyard, You can banish equipped monster: inflict damage to opponent equal to half the original ATK of the monster Banished by this effect.

 

Here is without the marks

 

Cannot be Normal Summoned/Set. You can Special Summon this card (from your hand) when an Effect Monster you control is destroyed by battle and sent to the Graveyard. Once per turn, you can Target 1 Level 6 or lower Effect Monster in your Graveyard: equip that target to this card (Max. 1). This card gains 100 ATK x the Level of the equipped monster. When this card destroys a monster by battle and sends it to the Graveyard, You can banish equipped monster: inflict damage to opponent equal to half the original ATK of the monster Banished by this effect.

[Beerus]

bump

[Nightmare Stomper]

It's a decent card you know :P I'd like to see it.

[Trebuchet MS]

Cannot be Normal Summoned/Set. You can Special Summon this card (from your hand) When an Effect Monster you control is destroyed by battle and sent to the Graveyard: You can Special Summon this card from your hand. Once per turn: You can target 1 Level 6 or lower Effect Monster in your Graveyard; equip that target to this card. (Max. You can only equip 1 monster at a time to this card with this effect.) This card gains 100 ATK equal to x the Level of the equipped monster x 100. When this card destroys a monster by battle and sends it to the Graveyard: You can banish 1 equipped monster; inflict damage to your opponent equal to half the original ATK of the monster banished by this effect.

I'm assuming that the Special Summon starts a Chain. Normally, inherent Special Summons that have no colons and thus have a "(from your hand)", etc, can only be conducted during your Main Phase.

 

I can foresee this card being used in tandem with high-power easily Summoned monsters with normally crippling downsides (think Goblin Attack Force) to trigger this card's Summon condition and inflict more damage with its effect. The issue I see here is that this card faces a hard-cap of 2500 ATK on its own, and thus would have some difficulty surmounting most boss monsters.