A Light Shines in the Darkness

[Radiant F.U.R.Y.™]

Activate only when your opponent's monster declares an attack while your Life Points are at least 2000 less than your opponent's, and your opponent controls at least 2 DARK monsters. Special Summon any number of your banished LIGHT monsters, up to the number of DARK monsters your opponent controls, ignoring any Summoning Conditions. Their effects are negated and they cannot be used as a Synchro or Xyz Material for a Summon while your opponent controls a face-up DARK monster. The original ATK of a monster Summoned this way becomes 1000 higher than the original ATK of the DARK monster your opponent controls with the highest original ATK.

[Love of Ghibli]

I like that it is a side deck card for dedicated light decks and it has a steep cost for what it does. 

On the other hand it is a little too imbalanced in my opinion. First it is a countertrap which is spell speed 3 meaning only other counter traps can stop it. Yet it doesn't actually counter anything. Counter traps trigger when a certain action happens not at any moment when the gamestate isn't in your favor.Secondly, it doesn't have a limit on what it can summon. As an Agent player it would be really hilarious to stare down to big bad boss dark monsters and then trigger this almost unstoppable trap card and summon Krystia and Hyperion (or any combination of Light Bosses).

For fixing it should probably first be a normal trap and there should be some limit. Like maybe LIGHT attribute that are of a certain level. I want to say 4 or lower but then that still leaves Bujins, Constellar, Stellarknights, and Star Seraphs with a lot of options.

[Radiant F.U.R.Y.™]

I really wanted this to be a counter trap. As far as a limit, I thought negating their effects was enough, but I can see how this can be abused. I'll scale it back a bit...let me tinker with it a bit.

[Radiant F.U.R.Y.™]

EDIT: Effect Updated