Forum:Helios Trice Megistus's multi-attack effect

"After this card attacks, it can attack once more if your opponent controls a monster." Compared to the other multiple attackers that have "If this card destroys your opponent's monster by battle, it can attack once again in a row" or "This card can attack all monsters on your opponent's side of the field once each," Helios' is a bit more confusing to me. So i have a few questions:

1. Does its "attack once more if your opponent controls a monster" effect have to be in a row?

2. If it destroys a monster like Giant Rat when Giant Rat the only thing on the opponent's side of the field, can the special summoned monster via Giant Rat be attacked again by Helios? After Giant Rat is destroyed, there's technically no monster on that side of the field anymore "after [Helios] attacks," right? The damage step baffles me so...

3. Does the "sfter this card attacks, it can attack once more if your opponent controls a monster" effect apply immediately? I think what i'm trying to say is if an effect like Scapegoat's is activated by the opponent of Helios' controller after their field became empty due to Helios' previous attack, can Helios attack again?

Sorry if I don't make any sense.

Thanks!