Also, both have strong connections to their mothers. Aemond very clearly vies for Alicent's approval as stated by Ewan, and Chara’s manner of speech is nigh identical to Toriel.

Both show a passion to push things to their extremes. Aemond strives to become the greatest ruler in the history of Westeros through studying and training, and Chara’s entire character revolves around the idea of of control and limit-pushing through their association with the number 9.

Aemond and Chara are both quite similar in the sense that they're both members of royal dynasties that are consumed by ego. Both were mistreated as children and that motivates their every action, making them consumed with a need for power and control.

Jaime Lannister the man that you are

At last, I can spread my Chara Aemond propaganda to the masses

I finally made it

a man in a black and red armor stands on stairs

ALT: a man in a black and red armor stands on stairs