Lady Darkness - Princess Of Evil

[Thanatos The Lord Of Chaos]

Lady Darkness - Princess of Evil ( Secret Rare )

Level 7

Attribute. Dark 

Type.  Fiend 

Atk . 2850

Def. 2600

Effect . This cannot be special summoned " except from your hand " by banishing 3 " Dark Attribute monsters " or by banishing 3 " Fiend Type" monsters from your graveyard   . When this card is special summoned you must banish 1 "Dark Attribute Fiend Type " monster from your opponents extra deck or this card is banished or sent to the graveyard ( your choice ) and then draw 2 cards and if they're "Fiend Type " or " Dark Attribute monsters " you can draw 2 cards and if the combined total of the monsters levels are  7 you add them to your hand " if not your opponent draws 2 cards " this card is " destroyed " or " removed " from the field you can special summon the card you banished that belonged to your opponent ignoring summoning conditions.  If you choose a XYZ card  you can add this card and the other cards that were used for this cards special as XYZ materials . 

[Dokutah]

I sense a pattern in most of your creation that they either work in a very situational way its almost borderlined dont work at all, overpowered, OR ironically doing both of those. Neither is clever or fun from both design and gameplay standpoint.

Extra Deck Banish is potentially overpowered not because of the banish but rather by rules players need to check for that specific monster to confirm the banish effect which you can use to peek opponent stuff. Its unfair in many ways

Wording is a mess, rough fixes:

Must be Special Summoned (From your hand) by Banishing 3 monster that either DARK or Fiend from your GY face-up. When this card is Summoned: You can Banish 1 DARK Fiend monster from your opponent Extra Deck face-up. When this card is removed from the field: you can Special Summon the monster that banished by the effect of this card to your field, ignoring the Summoning condition. If you Special Summon an Xyz monster this way, Attach both this card from your GY and all of your Banished monster that Banished by the Summoning procedure of this card.

[Darj]

The text is not so understandable. I cannot give an accurate fix or review when I cannot even exactly tell when an effect starts and ends. If you need help writing it, you can explain what the card is supposed to do and I can work from there.