SP [Koumei] build. Slap on [Galvanized Aptitude] and [Condition Overload] on any weapon and you'll be good to go with how much status you're afflicting.

Don't be afraid. Use your 1 and 4 anytime you see a group of enemies. With the amount of status you're inflicting, you're bound to drop energy orbs to keep using your abilities. If you're using [Duplex Bond] on your companion, then you'll really never run out of energy and can spam your abilities.

Arcane Impetus will stack up to x13 with your abilities, meaning an additional 78% strength and 39% efficiency.
Arcane Double Back will give you additional DR up to 75%. This is optional to have, but I find it useful in staying alive for level cap.

Duration is not a high priority since practically speaking, everything will be dead by the time the ability duration wears off. If you're still concerned, add however many red archon shards for duration until you feel comfortable. I wouldn't use more than 2 red shards for duration. The other 3 archon shards are up to you.

You can use [Archon Intensify] instead of [Umbral Intensify] if you don't want to use an Umbral Forma. I find [Umbral Intensify] more reliable than [Archon Intensify], but considering the chance you'll be hit by a stray bullet for your 3 to activate, [Archon Intensify] might work better depending on your playstyle.

You can replace [Adaptation] with [Rolling Guard] as well.
You can replace [Omikuji's Fortune] with [Augur Reach] if you don't have the augment.
You will need another Forma to replace [Power Drift] for [Primed Sure Footed]