The umbra forma is debatable. Could just run [Archon Intensify] and [Healing Return] on the melee. Up to you.

This build maxes out all the gladiator mods.

Don't subsume pull. Ever
Yeah, it's great for combo... or so you think. In dense lategame SP missions, the enemies are crowded anyway. Just slide attack through em and sleep them with your 2. Once you've built combo, Naramon prevents combo loss very well, so you just waste an entire ability slot for no reason. Instead, subsume Warcry, or Eclipse... or perhaps the chad Nourish.

Ability strength boosts your exalt's base damage, so it's nice to have. If you put electric damage on your exalt, you can benefit from the energy gain that [Archon Stretch] gives, granting you more than enough energy. Alternatively, you could opt for [Archon Vitality], and go for a heat build on your exalted weapons (which would require Arcane Energize, but again, it's up to you)