This character is from the otome Wizardess Heart. 

Felix was once a very gentle and empathic person who loved plants and animals. Due to this nature, Felix was the most hurt when humans betrayed him. Now, he is cold and rather intimidating. There is almost no negotiating with him. However, there will be a few times where he is a bit hesitant to carry out certain tasks. He even goes as far as to hearing the protagonist and her friends out in his spin-off(they want them to halt his plan of awakening Lacan). Despite his new personality, the old Felix isn't entirely gone. There are still some times where he can be gentle or smile. This side of him is ONLY shown in the spin-off/ending of the entire game.

Before the entire race disappeared, Felix was one of the leaders of the Dragonkins (human-like dragons). Being one of the 3 reciters (Dragonkins with eternal life and youth), Felix was the closest to humankind. However, when war broke out between humans and the Dragonkins, he felt betrayed, causing Felix to change for the worst. After the war, Felix was one of the last remaining Dragonkin sealed away in an underground labyrinth. 

During season 7+8(Lucious, Willem, Hugo, and Hisoka's routes), Felix is the main antagonist. Felix is always trying to kill the protagonist due to her real identity as The Goddess Of Time being a threat. His true motive is revealed to be awakening Lacan, which was a Dragonkin that was very close to him. Felix will do anything to achieve this goal, and goes as far as to kidnapping Hachi and holding him hostage in order to achieve a magical item called The Twilight Watch. After a certain battle with his brother (Willem), Felix goes missing until Season 11. In Season 11, Felix appears as "Slightly-Off Taffy" which is his disguise. 

Voice: Cold, any pitch (most preferably in the high to medium range). The colder the better. Felix loathes humans and wants nothing to do with them. He wants them to all drop dead, and this is especially shown in line 3.