My rework suggestion:
Decrease base hp at 0 rank to 300, (at max rank - 1200).
Same as current, but Inaros can consume Sand Shadows in downed state, each will increase revive gauge by 25%.
Same as current, but with additions of synergies:
Spread Scarab Swarm ability to all damaged by Desiccation enemies if at least one of them was affected by Scarab Swarm for 100% of remain duration.
Grant 100% confusion chance on damaged enemies if Inaros within range of The Eye of The Sandstorm ability.
Augment - Desiccations Curse: Killing blinded enemy with finisher and 2 seconds after finisher have +25% chance to spawn Sand Shadows for each Inaros different ability affected the target (note: if Scarab Swarm casted on target spawn chance will be at least 75%: 25% base Sand Shadows spawn chance from Scarab Swarm + 25% from augment for Scarab Swarm +25% from Desiccation).
2) Devour rework:
Inaros drain vitality of the enemy within 8m range (1s cast only, no long duration sucking of hp), dealing 500 TRUE dmg and increasing his own MAX HP by 100% of damage dealt by this ability. Max HP gained slowly decay to 0, decay rate increase with multiple casts.
Heal Sand Shadows by small HP% around you.
No range restrictions if casted on target affected by Scarab Swarm.
3) Scarab Swarm:
Same as current, but with small changes - (HOLD) instant cast which adds 25% Scarab Armor charge, each cast cost 400 HP and stops decay of Devour ability for short duration.
(TAP) - same 25% Scarab Armor charge cost, Scarabs increase damage taken of affected enemies, Scarabs don't passively spread and don't cause panic, 10s duration.
Enemies died with Scarabs active on them have 25% chance to spawn Sand Shadows.
Sand Shadows HP slowly decay over time (as Nekro's Shadows)
Augment - Negation Swarm: No changes needed.
4) The Eye of The Sandstorm:
Inaros creates sandstorm zone which slow down enemies and reduce their accuracy, also providing a chance of confusion proc on enemies to attack each other for short duration. Closer to the epicenter - stronger effects and higher confusion chance.
(HOLD) Consume all remain Scarab Armor charges to activate Scarab Swarm on all enemies for next X within range.
Sand Shadows will try to stay within The Eye Of The Sandstorm range which increase their damage and grant a them chance to evade attacks even from enemies outside of ability range.
Augment - Everlasting Scourge: Radius expand over time, +50% status duration on all enemies within range.