It allowed Thrud to apply kinetic energy to the spells, giving them mass and backing them with her physical might.
On top of that, Phantom Echo generated a second beam and Life Maelstrom increased the power of both spells tenfold. It was the best she could do since Thrud had no idea how to cast Blade Tier spells.
She had practiced with Arthan's set for centuries, but it was still a copy of something that Tyris had crafted for Valeron. After refining her body and Awakening both the Guardian's and the First King's blood she could now tap into the set's full potential but they were still a bad match.
Valeron had been a loving and protecting leader whereas Thrud was driven by rage and ambition.
Acala unleashed Rising Sun just in time, the Blade and the Spirit Spell clashed just a few meters away from him, but it was enough. Rising Sun was fueled by the ex-Ranger's deep violet core and Dawn's power core, both boosted to the next level by their synch.