CREATE TABLE table_204_721 (id DECIMAL, "rank" DECIMAL, "wrestler" TEXT, "no. of reigns" DECIMAL, "combined\ defenses" DECIMAL, "combined\ days" DECIMAL)

who is the only wrestler to have only 1 combined day ?
SELECT "wrestler" FROM table_204_721 WHERE "combined\ndays" = '1'
SELECT "wrestler" FROM "table_204_721" WHERE "combined\ndays" = '1'