I actually had problems while controlling Riku during the last battle. Maybe five or so attempts before I finished it. I tried to time the battle so that when it was his turn to fight, he entered with a full HP bar.

Supposedly: Getting 100% on Proud grants access to a special Paradox tourney that allows you to fight every main boss from KH, the new fights that were in CoM (the XIII people), and many of the main villians from KHII. He says that the Guide hints at this hidden tournament.

Can anyone confirm/deny this?

I was barely able to beat him at level 85. First you want to set yourself up with high defense armor and high attack rings. Load up your items with Elixirs as well. You also need the once again skill along with aerial recovery. MP haste and Ultimate Weapon are also a must.

The key is to use Reflect on almost a constant basis and hope you catch him with some reflect damage. Some of his attacks will reflect back almost an entire bar of his health worth of damage. Always watch for the reaction command as this will allow you to unleash an HP bar worth of combos on him. If he catches you on the ground and launches you up in the air, do an aerial recovery and you'll be able to break his air combo and start one of your own.

When he starts using that pillar of fire attack, you actually want to try to get into it and reflect that damage back at him. You'll take a bit of damage yourself, but I was able to right next to him when he did it and I reflected back about 3 bars of health back at him from a single fire pillar attack.

The Elixirs are for when he uses Sin Harvest. From what I've seen, its completely unblockable. When he uses it, do the reaction command then use an Elixir asap and start spamming Reflect.

Reflect, eh? I'll have to try that out next time I play. I managed to get him down to six life bars at level 61 with Oblivion equipped. I blocked most of his attacks and just waited for him to come at me, rather than give chase.

Sephiroth's fire pillars always ended up killing me though. No matter how far or how good I was doing, those would end up soldering my ass to the floor.

I'm now on L 65 also I got Ultimate Weapon,and I'll try to make L 99 but you can give me better armor & ring names to used when fight Sephiroth

first you need to have beaten the world Pride Land for the second time. You need the gullwing keyblade (talk to YuRiPa in Hollow Bastion to get it) and the ability exp boost(not sure about the name but you get it). Now you need a good magic attack, if your magnega kill it one shot, it's the best or take thundega.

Go to pride land, de-equip any healing ability or item from goofy and donald, go into a fight and let you get hit, because you will need to have your hp bar in red and hear the REALLY annoying sound that it do. Why? because the exp boost and the gullwing keyblade ability only activate when you are in red hp.

When your hp is in red, go on top of the pride rock (where you fight scar) there will be tons of monster there (those little yellow monster that you see for the first time in Mulan world in the mountain) Now it's time to use the magnega and you will kill them in one shotor you can kill them with the keyblade (it take more time but it's the same thing) each single monster will give you 100-160xp(sometime just 50xp) in one run you can do about 30000xp. so just exit and re-enter to kill them all again and repeat till you're lv99.

Last time I did that, I did lv50 to lv75 in about30-40min. so if you cen kill them one shot with magnega 2h-3h max and you are lv99^^

Sin Harvest is interrupted if you can jump and attack Sephiroth right as he goes "Sin....". Theres a window of about 3 seconds to hit him.
After he ends his little saying with "angel", its too late

You'll need High Jump Level 3 and the Aerial Dodge (where you can jump slightly higher) at lv 3 to hit him.

I just tried spamming reflect though, holy hell so THATS what reflect does X.X

lol, its pretty easy on proud.. except boss's, I think ive used all my mickey helps.. hes helped on everything so far.. including cerebrous.. I really hope he shows aganist xaldin for me