Its normal attack is is a sonic echoing attack on all at melee range. Its most powerful move is Sonic Killer, another echoing attack that has a chance to inflict Slow status. Brush Dive is a diving attack on one for weak damage. It can also use Constant Shine to place a character in Shining Body status.
The Ice Melody is an extremely weak opponent in every way for this stage of the game. It has very low HP and none of its attacks are at all powerful, the only one presenting even a slight danger being the Sonic Killer, due to the chance of Slow status. Just about any character can defeat one of these in a single full turn with a series of normal attacks followed by a strong Special Attack. If it uses Constant Shine to inflict Shining Body and morphs into a Sorbie, then just fight the Sorbie instead, which isn't really a strong opponent either.
In the PlayStation 3 version of Eternal Sonata, the amount of EXP granted for defeating this opponent was greatly reduced and is less than that of the Sorbie, unlike in the Xbox 360 version, where the Sorbie gives less EXP. The HP is also reduced in the PlayStation 3 version.