(C) This card cannot be Normal Summoned or Set. (U) This card cannot be Special Summoned except by Tributing 1 Armed Dragon LV7 on your side of the field. (1) By sending 1 card from your hand to the GY, destroy all face-up monsters on your opponent's side of the field.
The (C) Condition cannot be negated.
The (U) Unclassified Effect applies in the hand (this Special Summon doesn't start a Chain).
You can't Special Summon Armed Dragon LV10 with Level Up! because Armed Dragon LV7 doesn't mention Armed Dragon LV7 in its card text.
Can't be Special Summoned from the GY / banished, even if it was properly Summoned.
The (1) Ignition Effect activates & resolves on the field.
Sending 1 Monster Card from your hand is a cost. This effect can't activate while Macro Cosmos is active, since you can't pay the cost.
Face-down monsters are not destroyed.