Nightless Rose

• One of the few Guts CEs in the game
• Limited: Available from the Nero Festival event.
• Guts only triggers once

Since Berserkers have a lot of damage potential but in return take an equally large amount of damage. The Guts effect of this CE helps alleviate some of the risk that comes with fielding a Berserker.
In comparison to using healing effects Guts will allow you to survive any hit, even if the damage is more than or equal to your HP in exchange for only working once.

For tanks, this CE can be useful as a safety precaution when the tank doesn't have access to their suitability skills (Dodge / Healing). In situations where the boss gets access to their NP quickly, Guts allows the tank to survive through it.

Chauvelier d'Eon
Arash
Ibaraki / Berserkers

Table here: CE Picture -- CE Name --- Effect

Necromacy
Chaldea Lifesavers
Princess of White Roses

Rashoumon event (Ibaraki Douji event)

Murder at the Kogetsukan

Inheritance of Glory