yet often did these sad elves both thrall and free hear the voice of ulmo in the streams or by the sea-marge where the waters of sirion mingled with the waves ; for ulmo , of all the valar , still thought of them most tenderly and designed with their slender aid to bring melko 's evil to ruin. , then remembering the blessedness of valinor would they at times cast away their fear , doing good deeds and aiding both elves and men against the lord of iron .