Location
	You can draw Siren from Elvoret, during the fight in the Dollet Tower.

Siren
	Elemental: None
	Attack: Silent Voice
	Level	HP	Atk. Power
	3	391	223
	10	724	393
	20	1206	634
	30	1696	875
	40	2194	1115
	50	2700	1356
	60	3214	1596
	70	3736	1837
	80	4266	2078
	90	4804	2318
	100	5350	2559

Ability	AP	Opens		Ability	AP	Opens
MAG-J	Learned	None		MAG Bonus	100	None
ST-ATK-J	Learned	None		Move-Find	40	None
ST-DEF-J	Learned	None		SUMMAG+10%	40	SUMMAG+20%
ST-DEFx2	130	None		SUMMAG+20%	70	SUMMAG+30%
Magic	Learned	None		SUMMAG+30%	140	None
GF	Learned	None		GFHP+10%	40	GFHP+20%
Draw	Learned	None		GFHP+20%	70	None
Item	Learned	None		Boost	10	None
Treatment	100	None		L MAG-RF	30	None
MAG+20%	60	MAG+40%		ST MED-RF	30	None
MAG+40%	120	Mag Bonus		Tool RF	30	None

Siren has a non-elemental attack. This makes it safer to use her, than the previous GF's. With that said, her attack is weaker than the other three. The one nice addition to her attack is she attempts to silence your enemies.
The best ability Siren has is the Move-Find ability. This ability allows hidden draw points, and save points to be seen.
Treatment is a nice addition as well. With Treatment, you can cure any number of status effects with one casting. It is definitely a great thing when challenging enemies such as Malboro's.
Siren is also the first GF to have ST-ATK-J, and ST-DEF-J. You can now junction status defensive magic, as well as a status attack to your weapon.