When I get back home I'll fight him again using lvl 70 characters with natural stats. I fought him with 9999 HP the first time since I never used the 9999 limit breaking patch with this game. Since I had max def I took full advantage of the wizard bracelet but this time I wont. (Cloud is still gonna be maxed out but the fight should still be harder)
-EDIT- I fought him again today with the same party, Cloud, Barret, and Yuffie, all with max stats leveled in the high 80's, but this time I disabled "breaking the damage limit". I said I didn't use dizugo's (hope i spelled that right) patch before; I lied. Actually I used it to break the damage limit but what I meant when I said I didn't use the patch earlier was that I didn't use it to break HP and MP limits. I'm still using gjoerluv's (I hope I spelled that right) hardcore mod where Ruby Weapon is invincible
and Knights of the Round does absolutely nothing. I don't know if you edited the script that determines sephiroth's stats based on how many level 99 characters you have and if you cast KotR on Jenova or not, but I intentionally wasted 255 MP to cast a useless KotR on Jenova to make the final battle harder because it was too easy last time.
The rematch was incredibly easy at first. I had immunity to fire so on my entire party (contain + elemental on armor) so beta did nothing. Sephiroth's wing attack hit my 255 defense characters (without dragon force) for moderate damage, when it actually hit me. Barret almost died before I full-cured him and I had 2 characters under resist with Cloud under 3 dragon forces and getting "shield" or invincibility status every other turn, so I received no status changes and very little for the majority of the match. (Cloud went untouched for 5 whole minutes.) So then Sephiroth is almost dead and he starts casting "Meteor Raine" Since Yuffie and Barret were under resist, thanks to gjoreluv's mod, they could not be shielded or dragon forced (should've done that before I gave them resist) and thats what put them in critical condition. As the meteors rained they started a cycle of dying and reviving with final attack + life2 then sephiroth casts supernova and its game over. Because Yuffie and Barret had "resist" and because Sephiroth's Super Nova ignores all status immunities, yuffie and barret suffered severe status changes that
could not be remedied since resist prevents all status changes good or bad in gjoreluv's mod. Because of sephiroth's stupid unavoidable attack, Cloud, who had invincibility status, dropped to 1 HP after super nova and when I fed him an X potion, it had no effect (healing fails increase an "invincible" character's HP the same way attacking fails decrease it) and I ended up dying from poison.
I didn't live long enough to see heartless angel, but I've beaten him before I'm sure I can do it again. This time I'll level ALL my characters to 99 (using jenova of course) to see if that makes Sephy
even harder.