As his name suggests, Joka is mischievous and a little bit violent. He is extremely loyal to Ghadius and tries desperately to please him. All he really wants is to be recognized by Ghadius.

At the opening of Klonoa: Door To Phantomile, Joka appears to be quite the incompetent little henchman. In his first appearance, he inadvertently tells Rongo Lango's weak point, as well as other bosses' weakness to Klonoa. Joka also attempts to hide keys from Klonoa in Forlock Forest, but left most of the task to his lesser minions, the Flying Moos. However, after Klonoa's fight with Gelg Bolm, Joka transforms from a buffoon to a villain who is considerably more intelligent, and becomes a serious threat throughout the game's next few levels.

Joka's signature signoff is a long, taunting "Adios" which he first uses in Door To Phantomile after the Gelg Bolm fight, and later multiple times in Namco x Capcom.

For Joka, he actually does have an English voice, that being Dave Mallow, so if you could match that, that would be preferred. An example of his voice can be found here: https://youtu.be/LQAyHf0U2nA?t=119