Its not hard without KOTR... I beat him just with cloud and omnislash. A little glitch is. the duplication trick for items... look it up. Then just have cloud, and the mime materia. And everytime your limit guage is up... use Omnislash... then mime it, when you get low on health.. cure yourself with a mega potion or something like that. Though, when ruby's tentacles are in the ground, you gotta get rid of those first, or else you cant hurt ruby higher than 1 point of damage each hit.