Rime

Location
Rime is found in Ancient Lemuria, the sublocation near the city of Lemuria reachable by the boat and the Grind Psynergy. It is hidden in the southwest-possible patch of grass that you can't even reach physically. Standing two tiles to the right of it, cast Cyclone, and Rime will suddenly appear and jump into the lone statue in the center of the screen. Then use the Tremor Psynergy while facing the now-shaking Statue to make Rime appear again, and you can now collect it.

Description
When Set, it increases base HP by 10 and base PP by 6.

When Rime's battle effect is used, a unique holographic visual of two intersecting blue symbols apply to the target, and the target's Psynergy is temporarily sealed. This effect applies with full accuracy compared to the Bind Psynergy that often misses. It is identical to the Golden Sun Jupiter Djinni Luff.

Ability analysis
For what it's worth, Rime is far more useful than the Bind Psynergy because it can be relied on to do what it is supposed to, just as the previous game's Luff was quite useful in various situations. Compared to Golden Sun, though, a Psynergy-sealing Djinni is not as useful in The Lost Age because the amount of enemies with Psynergy abilities that would be worth using it on to limit their options meaningfully are few, if any, since it does not seal an enemy's ability to perform monster skills or normal physical attacks. However, it can neutralize some of Agatio's (and later the bigger Flame Dragon's) powerful psynergies such as Meteor Blow and Rising Dragon. Sentinel would only use his physical attack and Armor Crush; the effect of Armor Crush can be easily fixed with Iron and Corona. Frankly, there are many ways where using it on an enemy would be the opposite of beneficial; on Dullahan, for example, you'd be preventing him from using his comparatively harmless Psynergy spells and forcing him to only use his extremely powerful monster skills like Formina Sage and the summon Charon. The same drawbacks apply to Luff when it returns along with the rest of the original game's Djinn when Isaac's party joins Felix's late in The Lost Age.

Name Origin
Rime is white ice that forms when water droplets in fog freeze to the outer surfaces of objects, such as trees.