The ② effect will trigger even if it is returned to the Extra Deck or banished.
"Starlight Road" can be chained to the ② effect as long as you control at least 2 monsters. (However, Stardust will only be summoned if this effect is being activated while in the Extra Deck).
The ② effect will not trigger if it was face-down when removed from the field. (If it was attacked while face-down, it is flipped face-up, and does activate when destroyed by battle).
If this card is tributed to Tribute Summon a monster with a Trigger effect (i.e. any Monarch), the ② effect must be Chain Link 1.