Lan Xue looked at him with incredulity. Even if he was the pioneer on that system, called as Soul Cultivation, the difference between their Soul Senses should not be that big right? They were all at the power level of Mana Sovereign Realm powerhouses, after all.
Even though Seth had yet to officially step on that threshold, Lan Xue and Arwen knew that he was probably the strongest one among them. His battle prowess should already be strongly solidified in the middle-stage of Mana Sovereign Realm, possibly even reaching the late-stage.
They knew it, witnessing his battles. Lan Xue saw him battle uncountable powerful enemies time and time again, deep down inside the obscure abyss and she knew that she couldn't possibly do the same. Arwen on the other hand, saw him defeating Velgor in his prime, fueled by the desperation of losing sight of his future. She knew that it would have been impossible for her to do it, without sacrificing her life.
