The five lines are not on the same scale, and the grid hides it
Every wiki publishes charms as a five-by-three grid with a percentage in each cell, which invites the one comparison the data cannot support. Max HP at +70% and Attack at +7% are percentages of different bases, and nobody has published either base — so a reader cannot tell from the grid which is worth a slot on Koo, and neither can this site. What does survive is the comparison inside a line: what a III is worth over a I is a ratio, and a ratio has no units to disagree about. HP and Defense multiply by three and a half across their tiers. Skill Power multiplies by two. Upgrading a Skill Charm is worth, in its own terms, less than half what upgrading an HP Charm is — and no record can say that, because a record only knows about itself.
HP and Defense are the same three numbers
+20%, +40%, +70% appears twice: once on the HP line and once on Defense, identical at every tier. Two lines carrying byte-identical values is either a real design decision or one table copied into two rows by whoever transcribed it, and nothing we hold settles which. It is flagged rather than smoothed over because the difference matters to a reader: if it is a transcription artefact then one of those two columns is wrong, and the site publishing it does not say where its numbers came from.
Your charm has one rolled mod. The wiki lists the pool
This is the finding, and it comes from the only Charm panel anyone has read off the game itself. The panel prints “Boost Skill Power +20%” — exactly the published figure, which is the reason to trust the rest of the grid — and beside it a single extra effect, “Crit Boost 3”, where the wiki lists six for that row. So the Charm Effects column is the pool a charm rolls from, not the list a charm carries. Every guide reprinting that column as an item’s effects is describing something that does not exist, and a reader comparing their own charm against it will conclude their game is wrong. The same frame settles a spelling: the game writes Perfect Dodge, so “Perfecrt Dodge” is that wiki’s typo rather than a name.
Nobody has published where a single one of them comes from
Fifteen charms, five lines, three tiers, and not one acquisition location anywhere. Not a zone, not a drop, not a merchant. That is unusual even by this game’s standards — the recipe books have locations from two independent sources and the armors have an acquisition order — and it means the practical advice on this page has to be about ceilings rather than about routes. Plan around what the top of a line is worth, because you cannot plan around finding a particular tier.