Heliosphere Dragon

The effect "While your opponent has 4 or fewer cards in their hand and this card is the only monster you control, your opponent cannot declare an attack" is a Continuous Effect.

The effect "While your opponent has 4 or fewer cards in their hand and this card is the only monster you control, your opponent cannot declare an attack" is an effect that applies "your opponent cannot declare an attack" when the conditions stated in the text are met. Therefore, even if the condition "your opponent has 4 or fewer cards in their hand and this card is the only monster you control" is met due to the effect of a card activated at the time of an attack declaration or the resolution of a card effect after an attack has been declared, an attack declaration that has already been made will not be negated. (The attack will proceed as normal.)

The effect "Make this card's Level 8 until the End Phase" is an Ignition Effect. (It does not target.)

Even if there is no longer a Level 8 Dragon-Type monster on your field at the time the effect "Make this card's Level 8 until the End Phase" resolves, the effect is applied as normal. (This card's Level becomes 8.)

"End Phase" in the effect "Make this card's Level 8 until the End Phase" is read as "end of the turn." (Applied from July 10, 2014)