Because Breena is so efficient at loading up on +1/+1 counters I've leaned into it with a strong counter subtheme: we use those counters to draw cards off Dusk Legion Duelist, ramp with Scholar of New Horizons, have board wipe insurance with Felisa, Fang of Silverquill, and turn our team into lethal angels with Sigarda's Summons
If X is 7 or more, you may play cards you own exiled this way until the end of your next turn." The big problem here, as is often the case, is the use of the word 'may' at the end of the first sentence
Competitive rules are clear about maintaining a clear board state and distinguishing how disguise or cloak creatures entered and when
Cyberdarkness Dragon X DARK Level 10 [ Machine / FusionEffect ] ATK 2000 DEF 2000 5 "Cyberdark" Effect Monsters Must first be Fusion Summoned
This card is a generic Spell that can Special Summon any Level one monster from the deck
I know that that's because the Delve makes it so you have a customizable Escape cost, but I think I'd be happier with the card if it had "Escape - , exile two other cards from your graveyard" or whatever