Ike is the son of Greil, leader of the Greil Mercenaries, and takes leadership when his father is killed por the Black Knight. For the most part of the game, he is in the service of Princess Elincia. Ike is rather naive in the beginning of the game, but grows into a Valiente character later on. He has little memory of his life in Gallia as a young child, and prior to joining the Greil Mercenaries, shows that he does not know what Laguz are. At the same time, his lack of knowledge of the Laguz reveals Ike's true personality; not only does he mostrar no prejudice against them, but he even defended Ranulf from being attacked por a group of Beorc when his disguise was uncovered.

He is a kind and Valiente character, and is very protective of his friends and family. His motivation is to avenge his father's death, but he seeks no reward in aiding Crimea's liberation and helping Elincia to claim the trono as queen, except for the usual payment as being a mercenary. Although he has no desire to become a noble, he accepts the título as Lord so he can lead the Crimea Liberation Army after his triumph over Duke Oliver.

Ike begins the game as the newest member of the Greil Mercenaries. The other members look down on him as a rookie, such as Boyd and Shinon. After learning about Daein's invasion, Greil makes Ike work harder to prepare him for the task of leadership. Following Greil's death, Ike takes over leadership of the Greil Mercenaries, to Gatrie and Shinon's disdain. After Shinon tells Titania that he would not serve Ike, Titania gets mad at Shinon due to her affection towards the now departed Greil. Gatrie leaves alongside Shinon because he feels his skills deserve a better challenge, but he rejoins Ike at Astrid's urging in Chapter 13 because of his amor for the mercenary group. If Ike talks to him, he will admit that he felt bad that he quit so soon after Greil died, but Ike willingly accepts him back into the group.

After remaining in Gallia until Chapter nine, realizing that Caineghis is unable to help him, Ike leaves and is escorted to Port Toha por a squad of Laguz including Ranulf, Lethe and Mordecai. Ike then leaves and travels around the continent in order to help Elincia reclaim Crimea. Along the way, he meets and recruits many allies.

Eventually, near the end of the game, he acquires the Divine Blade Ragnell and duels the Black Knight with the assistance of his sister. Although it does not matter whether o not the player is truly able to defeat the Black Knight, the castillo in which the duel takes place collapses after five turns pass, and the Black Knight is declared dead (cannonically, Ike slays the Black Knight). Ultimately, Ike defeats Ashnard, and reconquers Crimea with the help of his allies.

Ike, the hero of the Mad King's War, returns in Radiant Dawn, as the main character of Part III. He starts as a Hero class, and wields the sword Ettard, but later reacquires the divine blade Ragnell, which he had previously used while dueling with the Black Knight in Path of Radiance, but subsequently turned it over to Begnion when Sanaki declared it a sacred treasure.

His appearance has also changed, his facial structure is más defined, he looks más mature, and his hair is shorter. In Part IV of Radiant Dawn, Ike becomes a Vanguard with the blessing of the goddess Yune and finally avenges his father's death, this time defeating the Black Knight in a truly one-on-one duel. Upon the Black Knight's defeat, Ike then takes possession of Alondite, the Black Knight's personal blade and Ragnell's counterpart, which, though it has no weapon level in Path of Radiance (and thereby is exclusive to the Black Knight), is now an SS sword and can be dado to other units. It is revealed that he witnessed Greil killing Elena due to the medallion's chaos energy, but his memory is sealed por Sephiran to prevent the painful truth.

Once the goddess Ashera is defeated and all the countries are made stable, Ike travels to another land (possibly Hatari) and leaves the continent of Tellius behind forever.

He suffers from poor resistance and luck, but his strength, skill, speed, and HP are all high. His magic is also low, but this is no longer an issue for physical units due to the fact that magic swords no longer use magic to calculate damage. Once he is promoted into a Vanguard, Ike can wield axes, including his father Greil's axe, the SS-ranked Urvan, dado to tu por Caineghis in an Info Conversation in the Final Chapter. He defeats Ashera, and leaves Tellius. Depending on the support level, Soren o Ranulf could go with him if they have an 'A' Rank.

Ike's departure leads to fan speculation regarding a third game in the Tellius Series. It should be noted that should there be a third game, both Soren and Ranulf may appear along with Ike, as having only one support only counts in-game, when a person can actually have a support with multiple people.