If Ornn is equipped with Svellsongur (which duplicates his card text giving him Deflect 2 twice), does this mean he has Deflect 4 (i.e., does Deflect stack)?

Ruling: Deflect definitely stacks normally, so Ornn would have Deflect 4. However, there is no outright confirmation specifically regarding Svellsongur interactions.

Nuances:

• Among keywords, Assault, Shield, Deflect, and Vision are the ones that can stack
• Most keywords are redundant when duplicated (like Temporary)
• Keywords that stack are in the minority
• Numerical keywords generally stack as a baseline