In an appeal from a Civil Rule 12(b)(6) dismissal, how have the Riveras argued that the assignment of a security is a nullity without a valid assignment of the underlying debt?

^3. The Riveras admit in their opening appeal brief that their legal argument - the one regarding the assignment of the security being a nullity without a valid assignment of the underlying debt - is new. See Aplt. Opn. Br. at pp. 16-17. Ordinarily, we will not consider issues raised for the first time on appeal. Scovis v. Henrichsen (In re Scovis), 249 F.3d 975, 984 (9th Cir. 2001). However, we have discretion to do so when: "the issue is purely one of law, does not affect or rely upon the factual record developed by the parties, and will not prejudice the party against whom it is raised." Dream Palace v. Cnty. of Maricopa, 384 F.3d 990, 1005 (9th Cir. 2003). Here, we will exercise our discretion to consider the Riveras' additional argument. Because this is an appeal from a Civil Rule 12(b)(6) dismissal, the parties have not yet developed any factual record.