10 Huge Revelations From Star Trek: Khan

At the time of their arrival on Ceti Alpha V, Khan was supported by his chief lieutenant, Ivan. Ivan is voiced by Maury Sterling, who previously appeared in the Enterprise episode Exile as Tarquin. From the start, Ivan is single-minded in both his ferocity and intent. He sees all augments as rightful leaders in any situation, with Ceti Alpha V being no exception.

He is quick to murder Hugo for speaking against Khan, and to protect Khan whenever needed. He is absolute in his hatred of the El Boreans, killing one simply because he could. Though this causes the cracks between Khan and he to shatter, he is unrepentant. He is absolutely loyal to augmented superiority. Once Khan begins to weaken, in his eyes, that means Khan has no more right to lead them.

Another cause for their rift is his aversion to Lt. McGivers. Her status as human, unagumented, sickens him. Taking any kind of direction from her, even when her expertise can help the colony, is too much to bear. Her attempts to stand her ground with him go nowhere and, by the time of his exile, there is only hatred on his part.

Ivan is a symbol of all that humanity fears about augments. He truly believes in their position as rulers and is committed to eventually breeding humanity out. On Ceti Alpha V, he finds a new planet to conquer, though his narrow vision leads him to his final conflict. His death at Khan's hand only serves to solidify Khan's position with the remaining survivors. 

In the end, Ivan may be responsible for the madness that engulfs some of those survivors - and is directly responsible for at least some of the discontent between the augments and the El Boreans.