Kaminaki Sekai no Kamisama Katsudou - Vol. 7 Ch. 39 - The Story of Raising but Not Raising a Defeat Flag in Another World

[BadHaremSchollar]

Sumannus has been the first god i had to google.

And its a pretty obscure and abstract one.

Seems to be the manifestation of violent night lightining for the romans and an absorbed etruscan diety.