Quote Originally Posted by Kalaska'Agathas View Post
I'd have to see the shadow dragon statblock to know for sure. It wouldn't work with the Dragon Breath/Enervating Breath combo, since the Shadow Dragon's breath weapon isn't one of those listed in the spell.
They are from Monsters of Faerûn pg.43.
This is their totally balanced breath weapon.
Breath Weapon (Su): A shadow dragon’s breath weapon is a cone of billowing, smoky shadows with an energy drain effect.
Creatures within the cone gain the number of negative levels shown on the accompanying table;
the saving throw to remove the negative level is shown on the table as well.
A successful Reflex save (against the same DC) reduces the number of negative levels by half (round down).
Code:
Age             Breath Weapon (DC)

Wyrmling:       1 (14)
Very young:     1 (16)
Young:          1 (18)
Juvenile:       2 (20)
Young adult:    2 (22)
Adult:          3 (24)
Mature adult:   4 (26)
Old:            5 (29)
Very old:       5 (32)
Ancient:        6 (34)
Wyrm:           7 (37)
Great wyrm:     8 (39)