Iron Will [Doon Cuebiyari] and Might in All Forms [Unique Jewel]

Strength gives a bonus to Melee Physical Damage.
Might In All Forms allows Dexterity and Intelligence from nodes in it's radius to count towards that bonus as though they were strength, increasing the value of the bonus.
Iron Will applies that same bonus to Spell Damage, in addition to Melee Physical Damage.