I'm building a ghost character with the siren prestige class from savage species and so far she seems to be decently powerful. The major problem is that frightful moan (i.e., her main trick) is horribly easy to counter ( being a sonic, necromantic, mind affecting, and a fear effect). Ideas for helping with this would be appreciated. Ideas for helping the character be effective even when her main trick is shut down would also be great. I'll be assuming 32 point buy and since I'm not building this character for an actual game, all sources are open except for 3rd party (though I would prefer to not have to use dragon mag). Ideally this character would be able to contribute in a tier 4 party and up and also be useful from level 1 to 16.
For feats I'm thinking ability focus and baleful moan which would stack with the Reverberation bonus feat for a 6+ save dc. That may be overfocusing though. Ghostly grasp is a must and maybe flyby attack so I can hide in a wall, dart out and moan, then go back into the wall.
For levels I would like 10 level's of siren. A bard base might be nice to take advantage of the preform ranks required for entry into siren and the charisma boosts siren gives.
Sorry if I'm asking to much, just trying to provide as much information as possible.
Thanks in advance for taking the time out of your day to help.