Black Horn of Heaven
Edison Card Text
①When your opponent would Special Summon exactly 1 monster: Negate the Special Summon, and if you do, destroy it.
No targeting
No Damage Step effect
Banlist • Unlimited
Interactions
Can Black Horn of Heaven negate the Fusion Summon from Future Fusion's second Standby Phase?!
Future Fusion's lingering effect Special Summons a Fusion Monster on the second Standby Phase.
No. The Summon occurs during an effect's resolution, so Black Horn of Heaven cannot be activated.
Can The Selection negate summons from card effects like Blizzard, or only inherent summons?!
The Selection is set and a player is Normal Summoning Blizzard or Special Summoning via effects.
It only negates manual/inherent summons, like Black Horn of Heaven. You can negate Blizzard's Normal Summon, but you cannot use it to negate the Special Summon performed by Blizzard's effect.
Rulings
edisonformat.net
This card can only negate the Summon of a monster while there is no ongoing chain.
It can negate:
● A Synchro/Xyz Summon
● The Special Summon of "Cyber Dragon" or "Machina Fortress" by its own procedure.
It can't negate:
● The Summon of a monster being Summoned during an effect's resolution, eg by “Call of the Haunted”.
● "Immediately after you do" effects, even if that effect was CL1.
edisonformat.com
Like “Horn of Heaven”, this card cannot be used against “Premature Burial”, etc. It can be used against inherent Special Summon effects like “Cyber Dragon” or “Dark Necrofear”.
You cannot activate “Black Horn of Heaven” when you Special Summon “Lava Golem” onto your opponent’s side of the field.