Jonlan

 Jonlan is an non-playable character (NPC) from the Rebelstar: Tactical Command tactical RPG, he is obviously over 30, which is explained by his brain resisting the skull implant.

Description
From the manual:

Jonlan is one the oldest, and grizzliest, rebel soldiers. He is in charge of training new recruits. He was once a highly respected leader. An incident occurred where many people perished in a raid where he commanded rebel troops. Although he was cleared of blame by the rebel tribunal, he opted for demotion out of a sense of guilt and responsibility.