This Craft Essence's effect is too little to be of use, as 5% defense maximum is pretty negligible and there are other 3★ Craft Essences that offer better defense bonuses at the beginning.
Since this is a 1★ Craft Essence, you'll most likely get this from Friend Summoning, so it is probably best to burn this CE for QP until you get a better defense-based CE (Azoth Blade at minimum)
Servants that can taunt enemies will appreciate this kind of CE as they will need extra defenses to survive the enemy's beatings. Some survivalist tanks may also appreciate the extra defense.
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