I cant seem to beat the spectral keeper in zanarkand ruins. He is just annoying. Everytime he beserks me then counters to every attack due to beserk until im dead. Can anyone help me plz?

1. Train alot (!!!) in Zanarkand
2. Have all characters and all aeons on overdrive
3.be sure to have none of your characters facing it (meaning none should stand on the 3 platforms it is currently facing, move anyone facing it when it turns)
4. cast hastega on your party as soon as possible.
5. summon Bahamuth as soon as possible and have him use Megaflare.
6.See if you can use remedies or magic when someone is berserked
7. as a second aeon, summon Valefor and let him use his second (!) overdrive technique, it should deal a lotta damage.
8. After that, just try to keep your party healthy, summon Shiva and use her diamond dust, Use the other's Overdive techniques (esp. Auron's and Tidus' ), summon any further Aeon if you want/have to and/or just beat the devil outta it.

Also when it indicates it's about to use hte bombs summon an aeon, use its overdrive and let it die rather then your characters.

Yupp, exactly.

if none of ur characters are facing it it will turn around and use beserk tail, i believe. so keep a sacrificial lamb out in front and keep (if you have it) auto life on him/her

Cast Reflect on it so Curaga bounces back to you.