True Draco Apocalypse (BLMM-EN177)

If this card is sent from the Spell & Trap Zone to the GY: You can target 1 monster on the field; destroy it. You cannot activate the following effects of "True Draco Apocalypse" in the same Chain.
• You can target 1 other "True Draco" or "True King" card you control; destroy it, and if you do, the ATK/DEF of all face-up monsters your opponent controls become half their current ATK/DEF (even if this card leaves the field).
• During your opponent's Main Phase, you can: Immediately after this effect resolves, Tribute Summon 1 "True Draco" or "True King" monster face-up.
You can only use each effect of "True Draco Apocalypse" once per turn.