Deleter Alpha (new idea trying to balance it out)

[Blacklion65]

Deleter Alpha
DARK/Machine/Effect/Level 10
This card cannot be Normal summoned or Set. This card cannot be Special summoned except by it's effect. When your opponent activates a Spell or Trap card during the main phase, you can destroy 1 Normal summoned monster your opponent controls, then you can Special summon this card (From your hand), you cannot activate other card effects, summon or declare a attack the turn you summon this card.
2300 ATK / 0 DEF

well i made a card for it but its too big...and i failed to notice this

[Im the prince of the ring!]

too broken. You're basically punishing your opponent by killing a monster of theirs and bringing out that monster. Ok. opponent uses upstart, blow up opponent monster, bring it out. OP

[Flash Flyer - Sakura]

The point of RC is to create balanced/well-designed. No part of this card is balanced, and know why?

 

It's inherently a +2 for you (1 for summoning this card and another for bombing your opponent's monster). Yes, it has a Nomi condition on it, but that condition means nothing since your opponent will activate a S/T card during the game at some point, and then this comes out.

 

Moving this to Joke Cards.

[Blacklion65]

Hmm how do I balance it then?

[Log-Lag]

You could restrict the activation time of the Card, and enable it in the Main Phase or Battle Phase only, so it would be less OP for the opponent.