Dragon card. need opinions

[Novias_The_ArchFiend]

[color=#5A5A5A][font=tahoma, helvetica, arial, sans-serif][size=3]Name: Dragon of Eternal Fire[/size][/font][/color]
[color=#5A5A5A][font=tahoma, helvetica, arial, sans-serif][size=3]Type: Dragon[/size][/font][/color]
[color=#5A5A5A][font=tahoma, helvetica, arial, sans-serif][size=3]Attribute: Fire[/size][/font][/color]
[color=#5A5A5A][font=tahoma, helvetica, arial, sans-serif][size=3]Level: 12[/size][/font][/color]
[color=#5A5A5A][font=tahoma, helvetica, arial, sans-serif][size=3]ATK & DEF: 4300/3900[/size][/font][/color]
[color=#5A5A5A][font=tahoma, helvetica, arial, sans-serif][size=3]Effect: This card cannot be Normal Summoned or Set. This card cannot be Special Summoned except by Tributing 3 Level 6 or higher Dragon-Type monsters on your side of the field. This card cannot be affected by your Opponents cards or Effects. This card cannot be destroyed by battle. This card can only declare an attack by sending the top 3 cards of your Deck to the Graveyard. During each of your Standby and End Phases, your opponent can Special Summon 1 Level 7 or lower FIRE monster from their hand or Graveyard. Once per turn, this card can destroy 1 "Shooting", "Nova", "Majestic" or "Archfiend" Synchro monster or "Dragon of Three Novas" your opponent controls, negating their effect(s). You must discard 3 cards to activate and resolve this effect.[/size][/font][/color]

[size=3]Revised Effect: This card cannot be Normal Summoned or Set. This card cannot be Special Summoned except by Tributing 3 Level 6 or higher Dragon-Type monsters on your side of the field. This card cannot be affected by your Opponents cards or Effects. This card cannot be destroyed by battle. This card can only declare an attack by sending the top 3 cards of your Deck to the Graveyard. During each of your Standby and End Phases, your opponent can Special Summon 1 Level 7 or lower FIRE monster from their hand or Graveyard. Once per turn, you can destroy 1 "Shooting", "Nova", "Majestic" or "Archfiend" Synchro monster or "Dragon of Three Novas" your opponent controls, negating their effect(s). You must discard 3 cards to activate and resolve this effect. If there are no FIRE monsters in your Graveyard, destroy this card. You can pay 2000 Life Points to Special Summon this card from the Graveyard. It is removed from play at the End Phase.[/size]

[Demon Loki]

Hard to summon.

Probably OPed, because it cannot be destroyed.

Sending 3 cards from your deck to the graveyard is no drawback. For example look at lightsworn or chaos deck. And also, makes it easier to activate Dragons Mirror.

[NeoRWBY65]

Summoning Requirement is easy to obtain if you have the right deck. Immunity to card effects and destruction by battle makes it a little OP. You have less than 15 attacks due to this card's effect. It kinda gets balanced out by the special summon effect, letting your opponent revive a Fire attribute to defend themselves in defense mode. Final effect seems to be a real tough one to use, being that specific and having to discard 3 cards to use the effect.

[Novias_The_ArchFiend]

This card is a counter-acting measure to the shooting, majestic, archfiend, nova and a fusion I made. He is a supreme finisher, but not about overkill, just to whittle down while they get to keep their defences somewhat decent. He is meant for decks with 50-60 cards to keep him alive. I'm considering adding a balancer effect like the earthbound immortals or the malefic monsters. Any ideas on that?