Just Health, Armor and 100% Knockback Immunity.
Umbra Intensify r0 just for the Set-Bonus.
(can be purchased for 100.000 Cephalon Simaris Standing in any Relay)
With his 4th Ability he will get 225 Base Armor to double his Armor. After that you eHP will increase to 89751 eHP.
If you use [Chroma]'s Elemental Ward with the Health Aspect you even increase your eHP to 99609 eHP, because of more 1219 more Health you will gain.
Arcanes:
- Arcane Grace is a must, because Inaros has only Health.
- Arcane Guardian or Arcane Victory is nice to have, but not needed at all.
- Arcane Strike and/or Arcane [Fury] can also be a good choice.
HoD Update:
Interesting Abilitys are [Garuda]'s Blood Altar, [Valkyr]'s Warcry or [Chroma]'s elemental Ward, but I think Inaror don't need anything for his own to survive even high Steel Path Missions.