Additions

The Legend of Dragoon's Addition system has already been briefly explained and (negatively) evaluated in my review of the game. Additions aren't special techniques, but regular physical attacks that are nevertheless unique to each character, not just regarding their effects, but the rhythm and speed at which the player has to give input for the attack to be executed successfully. Failure to press X during these timed triggers results in the attack ending prematurely with significantly reduced damage, whereas failing to press O when an enemy counters during Additions causes the character to take damage while not inflicting any on the enemy.

You can only set one Addition at a time by choosing it in the menu when outside of battle. Additions can be leveled up by using the same Addition over and over; the higher the level of the Addition, the more useful it becomes, capping at level 5 (80 successfully executed Additions). New Additions are learned when the character has reached a certain level, with the very last Addition only being unlocked when all other Additions of said character have been mastered. Higher level Additions have more hits so as to be more difficult to complete, as their rhythm usually gets trickier too. Different Additions vary in damage percentage and Spirit Point gain; leveling up Additions either modifies the damage or the SP gain, never both, which means that Additions specialize in one of the two. Therefore, you'll have to choose carefully which Addition to pick before a boss battle (since you have to stick with the same Addition throughout the fight) depending on whether you prioritize steady physical damage or steady and high SP gain, with the latter being used to enable Dragoon transformations.

Rose's Additions are relatively easy to hit and she has fewer Additions than other party members (Kongol being the exception), which means that obtaining her final Addition requires less time and successfully executed Additions.

A video of Rose's Additions can be found here. And yes, they sound suggestive (perhaps intentionally so to add to her "mysterious allure" and "mature charm" impression?) – just you wait until you see her Dragoon magic.

Addition Hits Damage SP Gain Learned
Whip Smack 1 100%
125%
150%
175%
200%
35
35
35
35
35
-
More and More 2 150%
150%
150%
150%
150%
30
45
60
75
102
Level 14
Hard Blade 5 100%
150%
200%
250%
300%
35
35
35
35
35
Level 19
Demon's Dance 7 200%
280%
360%
440%
500%
100
100
100
100
100
Mastery of all
Additions.

Equipment

Rose is shown using a one-handed sword throughout the game, inside and outside of battles, though the names of the weapons she can be equipped with include daggers and short swords. If you count instant death as an abnormal status infliction, Rose is the party member with the most weapons capable of inflicting them, although she isn't the only character with a weapon capable of instantly killing enemies.

Weapon Effect ATK
Rapier - 13
Demon Stiletto Frightens enemy with a given probability. 19
Shadow Cutter Weapon attacks become darkness-elemental. 24
Dancing Dagger - 30
Flamberge Stuns enemy with a given probability. 35
Gladius Instantly kills enemy with a given probability. 40
Dragon Buster - 100

There aren't many character-exclusive pieces of armour in the game (including headgear and footwear), though most characters share their available arsenal sets with another character within the party (female characters mostly have the same equipment, Dart, Lavitz and Albert can equip the same things, and so on). Each party member receives their character-specific elemental armour during the last parts of the game. Rose receives a character-exclusive headgear with unique properties.

Equipment Effect DEF MDEF MATK
Dark DG Armor Nullifies darkness-based attacks. 41 42 0
Rose's Hair Band Avoids instant death. 0 0 36