If I target Ornn, Forge God equipped with Svellsongur, do I have to pay Deflect 2 or Deflect 4?

Ruling: You must pay Deflect 4. When Svellsongur is attached to Ornn, Forge God, it copies Ornn's text (including Deflect 2) into its own effect text. Since attached equipment's effect text is active and appended to the unit's rules text, Ornn has two instances of Deflect 2. Because Deflect is a stacking keyword, these sum together for a total of Deflect 4.

Sequence:

• Ornn, Forge God has Deflect 2 as printed text on the unit
• Svellsongur attaches to Ornn and copies all of Ornn's text into Svellsongur's effect text
• Svellsongur's effect text (now containing Deflect 2) becomes active and is appended to Ornn's rules text
• The two instances of Deflect 2 stack, resulting in Deflect 4 total
• Any opponent's spell or ability targeting Ornn costs an additional 4 power to play

Nuances:

• Deflect is explicitly a stacking keyword - multiple instances sum their values
• Equipment effect text is active while attached and counts as part of the unit's text
• The equipment itself doesn't have Deflect; rather, it grants a second instance of Deflect to the unit it's attached to