6. Boots
Why Boots: Boots are vital for mobility and can offer resistances, movement speed, and defense, which can help you avoid damage and maintain your full health.

Legendary Affix Examples:

"Increased Thorns Damage While Healthy"

"Movement Speed"

"Increased Resistance to All Elements"

Synergies: Boots that offer extra movement speed, crowd control immunity, or resistances are ideal. The faster you can dodge incoming damage, the easier it is to stay healthy.

Recommended Boots:

Increased movement speed or crowd control reduction.

Elemental resistances or damage reduction.

Thorns damage increase or life regeneration.

7. Weapon (Optional but Helpful for Thorns Builds)
Why Weapon: Weapons can boost damage output and Thorns damage directly. While you may not want to focus too much on your weapon in a Thorns build, certain legendary weapons or two-handed weapons that increase Thorns or offer defensive stats can complement your build.

Legendary Affix Examples:

"Thorns Damage Increase"

"Increased Life Regeneration"

Recommended Weapon:

Thorns damage increase weapon.

Defense-oriented weapons with damage reduction or life regeneration.

Additional Considerations:
Class-Specific Gear: Depending on your class, you might have specific gear or skill synergies that further enhance Thorns. For example:

Barbarian: Use Shouts or Iron Skin to Diablo 4 Items stay healthy while dealing Thorns damage.

Druid: Utilize Werewolf or Werebear forms for added defense and Thorns scaling.

Legendary Affix Stacking: You can stack Thorns damage affixes from multiple pieces of gear to amplify your overall damage output. Prioritize gear that boosts both damage and survivability (life, resistances, etc.).

Bonus for Full Health: For Thorns builds, items with life leech, damage reduction, and resistances will be especially helpful in making sure you maintain full health to benefit from the affix.

By carefully selecting your gear with the "Increased Thorns Damage While Healthy" affix and defensive synergies, you can build a Thorns-centric character that excels at dealing massive passive damage while remaining hard to kill.
For Thorns builds in Diablo 4, weapons are not as critical as your armor and defensive stats, but they can still provide significant boosts to your Thorns damage. While weapons typically focus more on direct damage or specific class skills, you can still find options that either increase Thorns damage directly or offer helpful defensive stats to cheap Diablo IV Items keep you healthy.