Thor

Thor is the Nordic God of Thunder and regarded as the "Strongest Nordic God." He wields the hammer Mjölnir.

[Spoiler] He is the victor of the first round of Ragnarok, serving as Gods' Vanguard; he defeated and brutally killed the Humanity's Vanguard, Lu Bu. [/Spoiler]

(Source: Shuumatsu no Valkyrie: Record of Ragnarok Wiki)