Is this card balanced?

[The Fallen Tortle]

This is my first time creating a custom card. 

4 Level 8 Dragon Monsters

(Unaffected by Monster Effects). Once per turn (Quick Effect), you can detach 1 Xyz Material from this card to send all of your opponents cards in the GY and Banished Zone back into the Deck, then this card gains 200 ATK for each card sent into the deck by this effect. When this card leaves the field, you can Special Summon Monsters that was used as Material for this card. You can only use each effect of "Axel, The Supreme King Dragon", once per turn.

[Horu]

Given this is an Xyz monster, you need to be able to bring out those 4 Lv8 monsters to use as material. By standard game rules, you need to drop a total of 12 cards to summon this. That being said, detaching a material to essentially reset your opponent's deck and gain 200 ATK per card isn't bad. But a 3500 base is pretty decent but this thing likely wouldn't see play outside of a Blue-Eyes deck or something else that can bring out high level monsters in a jiffy. I mean, I like that it has a battle oriented effect since it can't be removed by other means. Makes sense to focus on its only real weakness. Honestly, the effect is worth using even if your opponent has 5 cards in the grave since resetting their deck gives this card 1000 ATK. So essentially, given that I have to give up 4 Lv8 monsters for a 3500 R8, I would like something that can stand up to the god cards in terms of power.

[Dokutah]

Unless using rank up shenanigans, i cannot imagine any scenario that effective at hard-summon this. The overall strenght of the entirely depend on how easy is the way to cheat this out. 

If this card is a standart 2 material. Then yeah its pretty strong. You shut down GY/Banish shenanigan while self-buff  for ar least a 1000. Has protection from best kind of card types and float to at least 1 material. Its good and actually pretty balance i guess.

So when you put those assesment back to the original 4 material then the obvious power down occur since you need to invest more so ultimately with those material this card suffer from overbalance 

a bit unrelated note, unless it is your intentional. This card is accidentally part of irl archetype Supreme King Dragon 

[Ray.]

Dude I think that the effect of gaining is Over Powered because may be there are so much cards in your opponent graveyard and its ATK points are already to much but if you made this effect last only for the end of the turn it will be better