Croire Explanation

While Croire is considered the default name, when you first get the elf you actually get a few name choices that have a bearing on gameplay.

Croire - This increases the drop rate of Life Energy capsules for Nurse Abilities Lv. 1 and Lv. 6.
Charité - This increases the damage done by the Animal ability for Levels 3 through 5 by one point.
Variable - This increases the damage done by Animal ability Lv. 5 by two points.
Progress - This increases the damage done by Animal ability Lv. 4 by two points.
Recrue - This increases the damage done by Animal ability Lv. 3 by two points.
Nouvelle - This increases the damage of the Hacker Lv. 2 ability by three points.

The abilities Croire can use are sorted into the same three categories that Cyber-elves were in the first three games. Like some of the other elves, she orbits around Zero during gameplay. At any time, she can copy one elf from each type, with a level less than or equal to her current elf level. By feeding her with E-crystals and leveling up the preferred type of ability, this Cyber-elf becomes more powerful as it grows through seven stages of evolution. If she copies a Level 7 elf, she also gets all the previous bonuses/abilities that don't overlap.

NURSE ABILITIES
Level 1 - Drops Life Energy.
Level 2 - Increases max vitality by +4
Level 3 - Increases max vitality by +8
Level 4 - Increases max vitality by +12
Level 5 - Doubles max vitality
Level 6 - Increases max vitality +16 & drops Life Energy (S)
Level 7 - Quadruples max vitality

ANIMAL ABILITIES
Level 1 - Increases running speed
Level 2 - Slows down wall sliding
Level 3 - Shoots flames straight forward
Level 4 - Shoots ice in an arc
Level 5 - Shoots homing lightning spheres
Level 6 - Saves Zero from pits ("Rises from pits")
Level 7 - Doubles the basic defense value

HACKER ABILITIES
Level 1 - Buster shoots four bullets in a row
Level 2 - Saber: press Up in triple attack for rising slash
Level 3 - Add 1 to power of Buster, Saber and Knuckle
Level 4 - Saber: Press Down in triple attack for attack wave
Level 5 - Enemies drop items more often
Level 6 - Doubles the effect of Life Energy and E-Crystals
Level 7 - Button combos to execute charged attacks or EX Skills (note: this doesn't really actually do anything because there are no button combos to execute charged attacks or EX Skills beyond what they already have and the level 2 Hacker upgrade, which you already get if you select this)