Stats: Gems

Agility Up: Increases agility by up to 50. Agility impacts accuracy and evasion, crucial against higher-level enemies. Can be equipped on Armour and Weapons. Best for Dunban and Reyn to maintain Aggro and for Dunban's Evasion tanking.

AP Up: Increases AP gained from battle by up to 200%. AP is needed to rank up Arts, with later ranks requiring 15,000+ AP. . Shulk benefits greatly due to costly Monado Arts.

Attack Plus: Increases a weapon's maximum damage by up to 50%. Affects auto-attacks, Talent Arts, and regular Arts. Can only be equipped on Weapons. Shulk, Seven, Dunban, and Reyn benefit due to high damage output and Aggro generation.

Attack Stability: Increases a weapon's minimum damage by up to 50%, leading to more consistent damage. Less important in Definitive Edition but still useful. . Benefits the same characters as Attack Plus.

Critical Up: Increases a weapon's critical hit rate by up to 25%. Critical hits increase the Party Gauge and trigger character skills. . Reyn, Dunban, and especially Seven benefit greatly.

Ether Def Up: Increases ether defence by up to 100. Affects damage taken from Ether-based Arts. Generally less useful as most enemies use Physical Arts, and defence can be boosted by equipment and Skills. . Melia could benefit due to low HP, but it's situational.

Ether Up: Increases ether by up to 150. Essential for characters who primarily use Ether-based Arts. . Melia, Sharla, and Riki are prime candidates; Melia for her Ether Arts, Sharla for healing, and Riki for DoT Arts.

EXP Up: Increases EXP gained after defeating an enemy by up to 200%. EXP increases character Level, impacting accuracy and evasion. . Prioritize the party leader or lagging characters.

HP Up: Increases maximum HP by up to 50%. Useful for characters with low HP. . Dunban and Melia are good candidates.

Muscle Up: Increases physical defence by up to 100. Generally a waste of a Gem slot due to numerous other ways to increase Physical Defence (Equipment, Skills, Buffs). . No specific character benefits significantly.

Strength Up: Increases strength by up to 150. Boosts auto-attacks and Physical Arts. Useful for pure damage builds. . Shulk, Seven, and Reyn are the best candidates.