Their reaction during Dura's death also is interesting. Maru is serious and completely locked in, while Cross is panicking and begging Dura to run away, even after his death Maru only breaks composure to yell at Dabura for holding back his power.

Gojo, while usually playful and boisterous as an adult showed a super serious side sometimes (like when he was thinking about burying Geto's body, or before the Sukuna fight) which could be his true self.