Blast Shield + Reinforced Bond for Firerate buff. If Equip Calculated Redirection it can maintain buff without Overshield.
Duplex Bond for some lure.
Enhaced Vitality for Companion survivability.
Loyal Companion for Warframe survivability.
Whiplash Mine for CC.
Vacuum for pickup things.

My own Plague Star related builds (2023/11/09). only text below this link have URL link to them.
Volt for AOE, Speed buff
Afentis for Firerate, reload speed buff
Pyrana Prime for boss killing
Vastilok for Armor Strip

Companion for Firerate buff
Companion Weapon for Support

Amesha for Lazy Defense

Kuva Grattler for AOE if you dont want to use Necramech