Don't know what to tell you
This is what I used and for me the final boss used gutshot.
We must be discussing
different bosses, but they were also called malmepholis and twins.
Ending of the sealed land area

.
I do remember facing his form the other way around though.
The line with 3 in them was on the top.
Maybe I approched from the other side or something lol.
Edit: This is the boss I am talking about. Herby showed a picture of him in his OP.
http://bbs.tynon.com/showthread.php?...ht=malmepholis