Does Svellsongur trigger Aphelios's ability twice when equipped to him?

Ruling: Yes, Aphelios will trigger twice when equipped with Svellsongur. The equipment attaches and immediately copies Aphelios's text to itself, then gives that text back to Aphelios, resulting in Aphelios having the text twice.

Sequence:

• Svellsongur attaches to Aphelios
• As it attaches, Svellsongur copies Aphelios's text to itself
• Once attached, Svellsongur gives the text back to Aphelios
• Aphelios now has his triggered ability text twice and triggers twice

Nuances:

• The "as this is attached" wording is key - it happens immediately during attachment, not after
• This is similar to other replacement effects like Nocturne's "as you look at or reveal me"
• Equipment gives text to the unit, and the unit will have the text twice (once original, once from Svellsongur)