Vegeta is a fictional character from the manga series Dragon Ball, created by Akira Toriyama. Along with Goku, Gohan and Piccolo, he is one of the most prominent characters in the series, originally starting out as a villain before becoming a mainstay hero. Vegeta starts out haughty, arrogant, self-entitled and ruthless as the prince of Saiyans. His royal status caused him to develop an inflated sense of superiority and he holds himself above most, if not all people he encounters. Regal, egotistical and full of pride, Vegeta was once a ruthless, cold-blooded warrior and outright killer. However, as the story unfolds, he changes to a person capable of caring about and loving someone other than himself. Vegeta was once a young member of the Saiyan army, but after his race's demise, he worked alongside Nappa and Raditz, directly under Freeza. He seeks immortality to rule the universe, but once he learns about Freeza destroying his planet from Dodoria, he resolves to take out Freeza (not to avenge his race, but to assure his own rule over the universe as well as to get back at Freeza for unknowingly using him to further his own goals). He later battles Freeza with the main cast on Namek and dies in the ensuing fights; once he is revived, he returns to Earth, where he adjusts to everyday life and remains there for good. In Cross Epoch (the Dragon Ball and One Piece crossover one-shot) Vegeta is the captain of an air ship and is seen wearing an eye patch and a cape with a clasp featuring the Kanji character for "vegetable." Trunks, Usopp and Nico Robin are members of his crew. (Source: Dragon Ball Super Exciting Guide, Character Edition)

Armin Arlert is Eren's best friend. He is physically weak, but emotionally strong. Even though he lacks in actual combat skills, Armin is a genius in theoretical courses and can make plans even under extreme pressure. Even so, Armin keeps on thinking that he is weak. He himself does not notice the things he does for Eren and Mikasa and believes himself to be completely incompetent and hates himself for having to rely on Eren and Mikasa. (Source: Wikipedia, edited)