The Bizarro Sephiroth Fight

[Banishing Blade]

Last time I played through i got 2 Parties in Bizarro Sephiroth fight.
Now that I played it again i got only choose 1 Party.
I think its pretty weird.

Usually you have to make 2 Parties in the fight and 3 characters get thrown away (depending that you got all), But for me i just got to choose 1 party and ALL the others except the three i chose got thrown away.

So anyone have any idea why this happens or what triggers it or is it random?

[Captain Maxx Power]

It is not randomised, and is actually based on a set series of values. This is all paraphrased from TFergusson's must-read Enemy Mechanics guide at gamefaqs.

You will face the single party version if any one of the following are true:

1. Jenova*SYNTHESIS achieved 13 or more turns before the countdown for
Ultima started. Note that this still counts turns where Jenova
couldn't do anything due to an Arm being dead. Also note that the
very first turn Jenova begins the countdown on does not count.

2. The average party level is 53 or less. Aeris is not included in
this count, and if you have skipped Yuffie or Vincent, then whoever
you've skipped will not be included either. The average is the sum
of your party's levels divided by the number of party members,
rounded down.

3. At least one party member is L34 or less. A character in this level
range automatically earns you the single party version of
Bizarro*Sephiroth.


This version of Bizarro*Sephiroth is the easiest and least complex of the
lot. The idea is simply to defeat the Main Body (Bizarro*Sephiroth A).
Complicating this is the Core (Bizarro*Sephiroth C) which heals the Main Body
every turn. At the start of battle, the Core is immune to any attack.
However, defeating Right Magic (Bizarro*Sephiroth D) and Left Magic
(Bizarro*Sephiroth E) makes the Core vulnerable to attack, allowing you to
shut down this healing factor.

You will face the two party version if you do not qualify for the single
party version, but one of the following is true:

1. At least one party member is L44 or less.

2. You are missing either Vincent or Yuffie or both.

3. The average party level is 67 or less.


This is a slightly more complex battle. Cloud's party will face the Right
Side of Bizarro, while your other party must face the Left. The battle
begins with Cloud. The objective, again, is to defeat the Main Body
(Bizarro*Sephiroth Main:A). However, the Right Core (Bizarro*Sephiroth
Main:C) is still healing it every turn. To complicate matters, defeating
Right Magic (Bizarro*Sephiroth Main and Main:E) is no longer enough to make
the Core vulnerable. It is necessary to defeat a part of Bizarro*Sephiroth
and *then* switch parties to Bizarro's Left Side.

There, the Left Core (Bizarro*Sephiroth Sub:C) is accessible. While still
immune to attacks, it becomes vulnerable when Left Magic (Bizarro*Sephiroth
Sub and Sub:E) is destroyed. Once the immunity is gone, Left Core may be
destroyed. Once both Left Core and Right Magic are dead, Right Core in front
of Cloud's party finally becomes vulnerable. Switching back to Cloud's party
and defeating it finally removes Bizarro's method of healing.

Alternatively, it is possible to simply overpower Bizarro by dealing more
damage than he can heal, which is often considered a much much simpler
method.

Note that when you switch parties, the HP values of all Bizarro*Sephiroth
parts are saved. When you return to that battle, it is identical to starting
a new battle (all statuses are reset, for example), except that the HP of the
parts are set to their saved value. Also note that any damage done to a part
in one battle does *NOT* carry over to the other battle; the AI script only
shares Death status, not HP. Thus, the HP for Bizarro*Sephiroth's head can
be different between two different parties, for example.

Finally, you will get the three party version if you fail to qualify for
the previous two versions. To be precise, this means that all of the
following is true:

1. Jenova*SYNTHESIS only achieved 12 turns or less before she began her
Ultima countdown.

2. The average level of the party is 68 or greater.

3. The lowest level character in your party is L45 or greater.

4. Both Vincent and Yuffie have been recruited into your party.


This is it. This time, Cloud's party stands dead center, the 2nd party
gets the Right Side of Bizarro and the final party gets the Left Side of
Bizarro. Defeat of the Main Body (Bizarro*Sephiroth Main:A) again is the
primary goal. However, you now have three Cores (Main:C, Sub1:C and Sub2:C)
to deal with. Only the center Core heals the Main Body, but it will only
become vulnerable if the two Sub Cores have been destroyed.

Thus the Left and Right parties must destroy Left and Right Magic
respectively to make the Sub Cores vulnerable, then, in turn, destroy these.
Once this is accomplished, you may destroy the Main Core at your leisure.
The Main Core *cannot* revive either of the Sub Cores, so once the Sub Cores
have been destroyed, there is no chance of the Main Core's immunity
returning.

Once again, you may decide that this is not worth it, and simply wish to
outdamage the amount the Core will heal.

Note that when you switch parties, the HP values of all Bizarro*Sephiroth
parts are saved. When you return to that battle, it is identical to starting
a new battle (all statuses are reset, for example), except that the HP of the
parts are set to their saved value. Also note that any damage done to a part
in one battle does *NOT* carry over to the other battle; the AI script only
shares Death status, not HP. Thus, the HP for Bizarro*Sephiroth's head can
be different between two different parties, for example.

A thorough enough answer methinks.