Sephiroth is very hard, even at the highest level. Learn his attacks and strategies, and create a counter-plan.
get alot of healing items ( and i believe your normally alone like the first one?, i had cloud and axel via cheats) like he said, counter plans, it took awile for me too, but i did it (did not use invinciblity cheat) - L
Like they said learn his attack strategies and create a counter-plan. I have found that being at least level 83 helps too. If you need even more help, turn to synthesis. Create the Ultima weapon and have a lot of healing items when you fight him. Good luck.
actually he really isint that hard
first:level up to 99 i know but its not that hard first get the keyblade gull wing it doubles exp in tight situations (low health)and the ability exp boost first go to pride rock and go to the menu and costamize donald and goofie so they wont attk or heal go to the very top of pride rock and jump in the air to make the enemies come down let them get your health low then go back down and give donald all of his attacks except cure give goofie only the atk that sucks in enemies go back up and start to kill using magnega to keep enemies from moving or attacking once you magic is high enough magnega will kill them by itself then just jump to keep the enemies coming and let the mp orbs rain like BLOOD but watch your health if it gets low go back down and DASH thru the save point to only heal in small prtions if done correctly you should reach it in no time.
second strategy and healing:first you'll need plenty of elixirs you can fight devastators who will drop them or synthesize them yourself you quick menu should have reflega thundaga the elixirs and curaga in the order of your choice.
third weapons and armor:well since no one really has the same setup armor and rings are yours to customize as you see fit just put on the strongest key blade you have i suggest the decisive pumpkin since it will increase the finishing moves strength after a long combo.
last to kill an angel:first start the battle as always using the reaction commands to to block his first attk the attak till he disappears then immediately lock on to him and get ready to tap square to block at the right time then x so you deflect a small portion of damage and lower his guard then combo him again he'll probably knock you into the air after the last combo if so regain you balance and use the quick menu to use reflega this will lower his guard then immediately lock on and preform an air combo reflega can also be used to deflect a number of other attacks including the dark balls he conjures around you but meteor is as far as i can see unaffected as well as the flaming pillars witch you can easily jump away from if your health becomes low make curaga your last resort since the lack of mp will leave you vulnerable to his massive air combos bu items cannot be used in the air so if you must well good luck if your health is low and hes about to use the slash combo block first or use the reaction commands then heal with elixir.....
sephiroth beaten in 3 trys lv: 87 all elixirs used key blade:decisive pumpkin armor and rings:...i cant remember but,cosmic arts,2 fencer earrings and the cosmic belt quick menu setup: triangel:elixir x 6 o:curaga x:thundaga square:reflega