Red Gem: Physical Attack +5, Physical Def -1
Yellow Gem: Critical Attack +7, Block Penetration -4
But Physical Attack gets multiplied by 1.5x during critical hits, so Red Gems actually gives +7.5 (probably rounded down) damage during it?
What’s the point of having an yellow gem in offhand…?
Without considering gem roasting the -4 Penetration also looks worse than -1 def.