Unlike most Berserkers, he has lost no sanity at all. Berserker is an intelligent and passionate man. He is a bright and mostly innocent lad who just wants the best for everybody. His is prone to some unfortunate moods wings where he becomes more angry and sorrowful, he knows they're certainly not constructive and does his best to control them.
Not knowing his parents in life, he desperately longs for such a connection and may become emotionally dependent of his master should they fit his category of 'parent' which at times can be a little broad.
His wish is for an untied Spain to become a world power and guide the future as it should… Don't believe it? Neither does Berserker. His wish is ultimately rather selfish. A world where children don't have to live without their mothers and fathers. Some magi could find this aspect of Berserker easily exploitable.
El Cid: Berserker's senior. He cannot help but look up to the figure of El Cid. Even though he replaced Berserker as the national hero of Spain, he feels no resentment and respect him greatly for his martial prowess and multiple victories while Berserker himself is famous for only one deed really.
"Look master. I don't care how much quartz you roll, I'm not calling him Senpai"
Roland: "Ahh. The great rival returns. You were the greatest opponent I ever faced… Maybe the greatest I will ever face. You seem far stronger than when I last saw you so who knows how this legendary rematch will go? Anyways although we were on opposite fields of battle I can't help but… Pardon? What do you mean you've never seen me before?! I killed you! …
That’s not what happened! I KILLED YOU THEN AND I CAN KILL YOU RIGHT NOW!"
"…Sorry, that was rude of me. You look the same but you seem so different and much more powerful than I remember. May I reintroduce myself?"
Sakata Kintoki: "Why do you always run for your mother? She just wants to love you! Do you know what it's like to never know the affection of a mother? You really should take them for granted. An overbearing parent is much better than one whose never around!"