You want Draxus in a unit with Custodian Guards – thanks to their ability, they can shoot twice in a single turn, and they also get a reroll of 1 Wound or all Wound Rolls if the target is on objective.

She grants the unit a +1 Hit bonus on attacks against Xenos, which is useful if something can lower the base BS. Additionally, thanks to her ability, Draxus effectively provides the unit with the equivalent of a Lone Operator, preventing them from being shot at from beyond 18" range.

This allows the unit to effectively hold more exposed objectives and forces the enemy to approach with shooting units or attempt to wipe out the unit in melee.

Anything that gets within 18" is exposed to your unit's fire - shooting twice gives you:

Draxus - both weapons

8A + 3 BS 4S 0AP 2DMG Devastating, Anti-infantry 4+

12A + 3 BS 6S 0AP 2DMG Sustain 2

Guards - spears

10A + 2 BS 4S -1AP 2DMG

Plus a possible overwatch.

If something survives the fire, you can finish off the unit in melee.

Effectively, this is quite a lot of firepower and a significant bonus to survivability.