He appears as a tall, thin man, holding a cup of tea, with a rather wacky moustache.
He often tells his opponents that he has prepared tea, as a welcoming to their army.
Additionally, he attempts to join the Eastern Army, and call himself the "Noble Fox of Dewa".
After successfully doing so, he plays a rather important role in supporting Date Masamune's forces during Sekigahara.
Role in Super Smash Sisters
Yoshiaki Mogami is a noble NPC in Super Smash Sisters. He uses his fencing sword and fights elegantly and gracefully like Krystal does. His supporting on his sword is like Yoshimitsu's. When he does a strange stance, he will attack anyone trying to hit it.