True Draco Apocalypse

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