Agni
Go to a well west of Tantar and Tuntar. Fish there to get a Slab. With the Slab, go to the cave by Romero where you filled up the WtrJr. This time, walk into the water. You will learn the dragon spell Agni, which does 999 damage each turn! I got this spell after I got Rudra. Tell me the earliest time you've gotten the spell.

Level Ups and Tri-Rang
On the island that Tyr's tower is on, you can fight lots of G.Slimes that give you 800 exp. But the cool thing is that sometimes you'll run into a M.Slime that gives you 9999 exp and 9999 gold! But before you fight them, you want to get the Tri-Rang behind the tower. Its the best boomerang in the game.

Chun-Li
Go to bleak and talk to the wannabe magician in the upper left house. Say yes to him, no twice, then yes. You'll see Chun-Li doing her Lightning Kick move.

Bo, Karn, and lots of Big Things
When you get the whale, you can go to Monster Island. It is at the most northern/southern part of the map. You can't see it on your map until you are either on or beside the island. On the island you can fight mega powerful enemies. You can also talk to two of your buddies from the first Breath of Fire game. Karn says he doesn't recognize you. I'm not sure what Bo is talking about, but it sounds like he's on crack.

Ways to defeat the Monsters.

The Huge Blob - Death spell.
The Huge Gonghead - He can do Cure 4 twice (I think), so after he cures once, hit him hard. Shot works sometimes.
The Huge Fly - ChopChop or Shot are your only chances of killing him quick.
Gold Slimes - AAHHHH! I save G.Drgn for these guys. they have 1000 hit points each, but its worth it! Just look out for there Death spell.

Dragon Spells
As soon as you kiss Jean, put him in the lead of your party. DON'T GO TO THE CASTLE YET! Go north above the water fall and. . . fall. Talk to the old guy with the hero.

Blue
When you get the whale, go south of HomeTown to a desert area. You should be able to see an area that looks like a spiral. Step on it to go into Blue's home. Talk to the ghosts and search the shelves for a Tolen. Then, go to the Magic School in HomeTown. Talk to a girl on the second story. Its Blue and she joins your team. She starts out at a high level with lots of spells. Her special ability, Shed, recharges her status and gets rid of any disease.

Infinite Money
When you need a carpenter, get the one in a normal house. When your town is built after defeating the witch, fill up the houses and make the town bigger. When it gets bigger, go to the house next to yours in HomeTown and talk to the orange haired guy. Let him start an item shop at your town. While in HomeTown, get around forty shrimp. Go to TownShip and buy as many Condition Ups from the item shop as you can. Go to the carpenter (who happens to be a cook) and use three Condition Ups and one shrimp to get to Gold Bars! Sell them at the item shop, buy more Condition Ups, you get the idea.

Cool Sword
When catch the Upaura (Excuse the spelling, can you remember how to spell it?), let it go. You'll get one of the best swords in the game.

Second Ending
When you get a town, go into the well. By Tunlan, there is an island with a town on it. Go into the town (Gust/Gant) and go to the back building. Go behind the back-right shelf to find a hidden room. Talk to the lady there and let her come to your town. When you have to fight the Old Man and Guard Eyes, DON'T ATTACK THE OLD MAN! You may be anctious to use your G.Drgn, but don't do it. Use ice spells on the bottom eye, fire spells on the left, and powerful ones on the right. Make sure you kill the right eye first, he casts Cure3 every turn. Afterwards, go down to the well and talk to the lady. Happy Trails.

These are all from www.segasages.com except for the top one.
I'll put up spme of my own tips when I figure them out...

No Training Beyd
from [email protected]
You don't have to train Beyd. Just wait for Zig to look at Shadis and attack.

Control the Kaiser Form
from Demonslayer ([email protected])
When you choose the Kaiser, most of the time Ryu will be out of
control. Choose "Infinity" and "Failure" as your ONLY genes and
Kaiser will be under your control.

 Deis
from Nick Nottoli ([email protected])
To get Deis go to Zublo Mountain AFTER you free her. All you have to
do is go up the stairs when you enter Zublo Mountain, go up to the slab
and press X. She will ask if you would like to be her apprentice.

Note: you might have to go back there a few times because she will not
apprentice RIGHT after you free her.

Easy Ghosts
from Mushroom Boy ([email protected])
If you're having trouble beating the ghosts in McNeil Manor, use Heal
on them. This even works on the boss.  

Free Berries
from [email protected]
For free berries go to the coffee shop and kick the tree with apples in it
for berries the berries give you 5 hps back.  

Master of Agility
from J.D. ([email protected])
To get the fairie Meryleep to become your master, go east of Wyndia
where there is a spring that is said to be home of the fairies. Have Peco
run and knock a rock into the middle of the pool, and a fairie will
appear. She will send you on a mission to get an object stolen from her
by a crow. Then go to the mountain west of the Arena, and if you walk
behind the mountain a "?" should appear. Enter have Peco hit the tree
with the crow on it. Take the object back to the fairie and she will offer
to be your master. Your agility will go up +2, but your Hp, Power, and
Defense go down -1.

 Quick and Easy Training Method for Beyd
from Sakura ([email protected])
I found a really quick way to train Beyd for his fight against Zig. I had
Momo and Nina in my party. First of all, make sure you have 99 healing
herbs(you'll need them!) Be sure to buy Beyd a Moon Sword and a
Breastplate so he will have a weapon and armor...you can't train him
without them. Remove all armor from all people in your party. This way,
Beyd can do more damage to you and his attack power will raise faster.
Nina had the assist spells Blunt and Weaken. Cast both spells on Beyd
to weaken him so ypou do more damage to him and his HP will rise
rapidlly. Have your party in the Attack formation with Momo at the
front(position 1) Have Nina cast weaken first until it affects Beyd. Have
Ryu (and Nina, after Blunt and Weaken have taken effect ONCE)heal
Beyd evry round and Momo attack. Have Nina and/or Ryu attack with
Momo ONLY if Beyd is fully healed AND dodged Momo's attack the
previous round. Using this method, I trained Beyd 8 times. Before the
8th training set of rounds, re-equip all characters. Using this method, I
trained Beyd so well, he was kicking MY butt!! Once this is done and
the fight between Beyd and Zig begins, Zig was doing 1 HP damage to
Beyd and Beyd did about 60-65 HP damage to Zig. Note: Don't have
your characters do anything but defend the whole Beyd vs. Zig fight. It
will only cause the fight to end earlyer than needed. Good luck!!

The Magic Master (Mygus)
from Nick Van de Houten ([email protected])
After you have gone a while through the game, go north of the town of
McNeil and you will see a tree stump on the map (a question mark will
show.) Enter it and go up and you will see and old man, talk to him.
Whichever character that is apprenticed with him will gain more INT
and AP, but gain a little less Attack Power and Defense during
level-ups.  

The Master D'lonzo
from RyuBOF3 ([email protected])
Near Windia, there is a coffee shop. Go behind it and there should be a
girl walking around. You need 15 different kinds of weapons to get her. 

The Master Emitai
from LeonRE2 ([email protected])
After you get older, you can get Emitai as one of your Masters. ( Emitai
is the leader of the second team you fight in the Tournament of
Champions) After you get older, you go near Ogre Road and there in a
path that you go to on your north. There is a hut. Talk to Emitai and he
will tell you that if you pay him 10,000 zenny for his mortgage, he will
teach you some of his spells.  

The Secret Master
from Nick Van de Houten ([email protected])
After you go to Windia the second time, there is a master. The way to
get to him is: See the walls surrounding Windia, there is a pathway
beetween the walls (just a tiny incy wincy south), continue to go through
this way and you will enter a little house. In this house is a Master.  

The Strength Master (Bunyan)
from Nick Van de Houten ([email protected])
After you get farther in the game, go back to Bunyan's Cabin to make
him a master for one of your characters. Any character apprenticed to
Bunyan will gain more Attack Power and Defence, and a little less
Intellegence and HP when gaining a level.

Thieving
from [email protected]
While walking around towns and such you can steal a few zenny's here
and there. Give the people a wack with your sword and they will pop
out. Usually about 4 to 6 each time. This will even work on dogs and
other animals.

 Weretiger!?!?! No Problem!!
from The Kub ([email protected])
As you know when Rei rejoins your party he gains the awesome spell
WERETIGER. The only problem is he some times attacks your party.
Solution... In the begining of the game learn INFLUENCE from a
BOSS GOBLIN (Pink Colored). Then after he rejoins have a slower
character use it when he morphs.

<Note from Hero: Make sure you do Influence on who you want Rei to attack.>