Revealing a Spell Card is a cost.
If you activate "Inferno Reckless Summon" when "Proto-Cyber Dragon" is Summoned while you have 1 "Cyber Dragon" in your Deck and 3 "Cyber Dragon Zwei" in your GY and only 3 Monster Card Zones open, you choose which monsters you want to Special Summon. Any monster that you cannot Special Summon is sent to the GY.
The leftovers aren’t sent to the GY. Source: OCG database.)
When "Cyber Dragon Zwei" attacks, it gains 300 ATK at the start of the Damage Step and keeps it until the end of the Damage Step.
If "Cyber Dragon Zwei" is being treated as "Cyber Dragon" by its own effect and "Skill Drain" is activated, the name is still treated as "Cyber Dragon".