modify the note's terms, those modified terms were what Green Tree was assigned. (See Mod. Agreement); Morse Elec. Prod. Corp. v. Beneficial Indus. Loan Co., 90 Wn.2d 195, 579 P.2d 1341, 1342 (Wash.1978) (holding that an assignee cannot acquire any rights in excess of what the assignor has the ability t