Fenrir you get after you beat Sephiroth and it has 7 strength, but it has negative combo.
Ultima is from a recipie, it has 6 strength and has MP Hasteaga.

It depends on what your looking for if your looking for a high magic and strength then
ultima weapon (i will tell you how to make in a moment) as it has 6 strength and magic
but if your looking for all out power and hardly and magic then fenrir is for you with 7
strength and only 1 magic its a powerhouse but as a downside it has negative combo. For
fenrir you beat sephiroth i will give a walkthrough if you message me. Ultima weapon? Now
that is a bigger much harder story that i will explain now. This is the hardest recipe in
the book. The materials you need are 1. Orichalcum+ = 7 2. Orichalcum = 1 3. Mythril
crystal = 1 4. Dense crystal = 1 5. Twilight crystal = 1 6. Serenity crystal = 4 7. Energy
crystal = 1. You can find the recipe for ultima weapon in a large chest i am not sure
where i think it is agrabah in the tower just before the boss fight with jafar (that is an
"i think") you will need to have 1 energy crystal to half the amount of materials you need
as the list i just gave you is the list of materials halfed as originally it will say
there are 13 orichalcum+ needed there are only seven so it must be halved i will tell you
about those last i will go through the materials by number 2. Orichalcum : these can be
very hard to obtain for them you will need to find the rare heartless called bulky vendor
which has a reaction command ability that when used drops materials it is found
occasionally in these places : the land of dragons (checkpoint) beasts castle (west hall)
agrabah (bazaar) halloween town (candy cane lane for this spot they dont appear straight
away if a message appears saying there is a rare heartless in the area you must go and
spin the merry-go-round to release them) olympus colloseum (cave of the dead entrance) i
reccommend trying to go between halloween town and olympus colloseum as these places
dispense not one but two bukly vendors. To use the bulky vendors ability you must go up to
it and press triangle now they release etter materials the longer you wait (as there
health gos down as you leave them) but orichalcums are released on any time not always
but sometimes. 3. Mythril crystal : these are harder as they must be made through a
synthesis recipe using the following materials : dense crystal - 1 found in the world that
never was by destroying berserkers which are found in naught skyway, addled impasse and
naughts
approach. Dense gems - 2 found in the world that never was by destroying samurai in
naught's skyway and naughts approach. Twilight crystal - 1 found in the world that never
was by destroying sorcerers which are found in nothings call and ruin and creations
passage. Twilight gem - 2 found in the world that never was by destroying assassins found
in hll of empty melodies (upper). With these you can make a mythril crystal. 4 dense
crystal : these are gained by destroying berserkers in the world that never was they are
found in the locations naught's skyway, addled impasse and naughts approach. 5. Twilight
crystal : these are found by destroying sorcererd in the world that never was they can be
found in nothing's call and ruin and creations passage. 6. Serenity crystals : these are
a bit more tricky these are also found from destroying berserkers which are found in
naught's skyway, addled impasse and naught's approach but they will not always drop them
only occasionally so you need a lot of patience to get these 7. Energy crystals : these
are again tricky to find as they are not always dropped only sometimes (same as serenity
crystals) they can occasionally be found by destroying bookmasters which are found in
radiant garden in the borough location patience is again a key factor. 1. Orichalcum+ :
these 7 and only seven materials are the hardest to find in the whole of kingdom hearts i
will tell you the seven locations in order. 1. In the world that never was just before
you enter organization 13's stronghold (the location is called the brink of despair) just
bfore you go onto the ramp look to your left, to your left there should be a chest just
cradled on a small bit of earth this is your first orichalcum +. 2. Comleting the entire
100 acre woods storyline (message me for walkthrough)will grant you the very generous
gift of another orichalcum+. 3. In the olympus colloseum (after defating xemnas in the
memorys skyscraper battle) if you have done the first 3 cups there will now be a fourth
named the goddess of fate cup, this cup is very difficult and will reuire patience to
complete but
completeing the cup will grant you your third orichalcum+ 4. The world atlantica (the
little mermaid stroyline) is the next key to our fourth orichalcum+ its very simple all
you need to do is complete the storyline to gain your fourth half way there now. 5. In the
world space paranoids just before you go into the final boss room (this is the location
named central computer core) there are two small and two large chest in one of these there
is another orichalcum+ 6. In twilights town (location sunset terrace (train location))
there is a train you can jump onto when you do this wait for it to pass a small building
with a chest on top (there are two buildings with chests on top so check both) there will
be your sixth orichalcum+ 7. This is the hardest of them all in my opinion to get this
orichalcum+ you must find every single material in the game if you want the walkthrough
for this you will have to message me but after you collect them all and you gain your
last orichalcum+ make sure ou exit the moogle shop then go back in so it can have your
last one. With all these materials you will have the right tools to make the ultima
weapon. One little thing is you will have to be a level 3 moogle to be able to be able to
use
serenity materials and a level 2 to use bright and energy material once your at this level
your all set. One tip for collecting materials is to equip your self with the sweet
memories keyblade which enables the lucky lucky ability which increases the drop rate of
items
also the staff metoeor staff can give donald lucky lucky and genji shield gives goofy the
lcuky lucky ability also all three of them have the ability lucky lucky which you can
equip. I hope that this walkthrough has helped you all and im sorry for any spelling
errors please thumbs this up bye.