Activating, but not canceling, a dragon transformation fully recovers Ryu's HP. Each form also provides a percentage bonus to Defense Power and replaces his normal attack with a spell determined by the form. Though he loses his usual chance to counterattack, he can still get critical hits, even though spells normally can't critical. His Attack Power is also set to a fixed value determined by the form, but this has no apparent effect since spell damage is unaffected by it.

When in this form, Ryu's normal attack is replaced by a spell that targets a single enemy and inflicts a base of 100 ice damage. Attack Power is 40, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

English Breath of Fire 3 uses the name "whelp" for these forms, and while it's less true to the Japanese, it works better in English.

When in this form, Ryu's normal attack is replaced by a spell that targets a single enemy and inflicts a base of 115 fire damage. Attack Power is 140, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

When in this form, Ryu's normal attack is replaced by a spell that targets a single enemy and inflicts a base of 130 jolt damage. Attack Power is 160, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

When in this form, Ryu's normal attack is replaced by a spell that targets all enemies and inflicts a base of 190 ice damage. Attack Power is 180, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

When in this form, Ryu's normal attack is replaced by a spell that targets all enemies and inflicts a base of 210 holy damage. Attack Power is 260, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

Note that the Fire Dragon does NOT inflict fire damage. On the plus side, few enemies are weak against fire that aren't also weak against holy.

When in this form, Ryu's normal attack is replaced by a spell that targets all enemies and inflicts a base of 225 jolt damage. Attack Power is 280, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

When in this form, Ryu's normal attack is replaced by a spell that targets all enemies and inflicts a base of 250 holy damage, but only affects Undead enemies. Attack Power is 300, Defense Power is increased by roughly {xx%} of its value at the time the form is activated.

While the Holy Dragon outdamages the Fire Dragon, it also costs significantly more, and can only damage Undead enemies.

When in this form, Ryu's normal attack is replaced by a spell that targets all enemies and inflicts a base of 320 jolt damage. Attack Power is 400, Defense Power is increased by 40.625% of its value at the time the form is activated.

When in this form, Ryu's normal attack is replaced by a spell that targets all enemies and inflicts a base of 999 jolt damage. Attack Power is 500, Defense Power is increased to double its value at the time the form is activated, and maximum HP is increased to eight times its normal value (capped at 999).

However, this form combines ALL party members. The transformation cannot be activated when any of the eight characters is Incapacitated or has any other negative status effects, or when any other fusions are active. For obvious reasons, no other character can take any actions while the form is active, either.

You'll need the Final Power for plot reasons, but an uncombined party should have little difficulty outdamaging it.

Activating, but not canceling, a fusion fully recovers Danc's HP {I think?}. Each form also provides an immunity to most, if not all, negative status effects, excluding instant death. While in a fusion, Danc's maximum HP is multiplied by the number of characters in the fusion, but the amount of damage he takes from physical attacks also seems to be multiplied by the same amount (it's unclear whether this is deliberate or a bug). The fused forms also get a damage bonus (possibly by the same factor?) but otherwise use Danc's equipment and attributes.

A fusion cannot be activated when any of the involved characters is Incapacitated or has any other negative status effects. Additionally, while the fusion is in effect, none of the fused chracters can use their normal field abilities, and only Danc (as the fused form) may appear in combat.

Combines with Gilliam and Manillo. Functions like Gilliam in the field, but with improved hunting abilities.

Possibly named after the Lockheed AH-56 Cheyenne attack helicopter.

Combines with Bilder and Manillo. Only usable underwater, and must be canceled to leave the ocean.

Possibly named after the Egyptian Temple of Debod, now in Spain.

Unfortunately, this form isn't available until after the plot points that take place underwater, making it nearly useless. A shame, really.

Combines with Gilliam and Bilder. Can move obstacles too heavy even for Bilder.

Possibly named after an abbreviation for the Toyota Land Cruiser (ランドクルーザー).

Combines with Gilliam, Bilder, and Manillo. Can open specially marked doors on the world map with an ultrasonic shriek. Randomly uses a rolling attack in combat that inflicts extra damage, which stacks with a critical hit when applicable.

The name has no apparent meaning.