Durandal isn’t the only Immortal Blades member getting a battlesuit in the 5.5 Honkai Impact 3rd update, as Rita Rossweisse will too. MiHoYo detailed the a Spina Astera battlesuit that is on the way. This is an S-rank MECH type. She deals fire-based damage in battle. She’ll also be free to acquire, provided people go through the Spring Treasure event.
Rita tends to use her scythe for her Spina Astera attacks. For example, her basic Canis Major: Sirius attack has a basic combo. That combo can deal fire damage and essentially burn an opponent if she’s in Astral Harness.
With other abilities, her Astral Harness state and the presence of a Void Vortex can alter possible attacks. So if you use the Coma Berenices: Cluster charged attack when both are active, there will be more fire damage dealt and other attack options available. If she’s in Astral Harness, using her Andromeda: Nebula evasion could increase her Blazar or heal her.
Also, this shouldn’t be surprising, but her Pisces: Alrescha ultimate causes Astral Harness and summons another Void Vortex.
Honkai Impact 3rd is available for PCs and mobile devices. Its 5.5 update will arrive on February 24, 2022 and bring the Spina Astera and Palatinus Equinox battlesuits with it.