If you don't already know who Espio is I'm gonna put his character bio from his first game in Japanese and here's Sonic Channel for safe keeping.

Sonic Heroes:

The analyst of the Chaotix Detective Agency. He is a chameleon with ninja skills. Taciturn, calm and collected. He has a stiff, military-like way of speaking. He is cautious to the point of going to extremes, but he occupies an important position as a weight on Team Chaotix, which tends to be optimistic and full of high-spiritedness.

He is the type who gets more passionate about dangerous missions and is quite confident in his ninjutsu, but he feels it is his credo to stay in the shadows, just like a ninja. (For example, even if he helps someone in need, he will never announce himself on his own.)

He is able to make himself invisible, but he sometimes makes the mistake of sneezing, which reveals his true form. His trademark is his large protruding horn and long, curled tail.

Sonic Channel:

The analyst of the Chaotix Detective Agency. He is a chameleon with ninja skills.

He is calm and quiet, and is cautious to the point of going to extremes, but he occupies an important position as a restrainer in the Chaotix Detective Agency, which tends to be optimistic and full of high-spiritedness.

He is the type who gets more passionate about dangerous missions and is quite confident in his ninjutsu, but he feels it is his credo to stay in the shadows, just like a ninja. He is able to make himself invisible, but he sometimes makes the mistake of sneezing, which reveals his true form. His trademark is his large protruding horn and long, curled tail.

For a reference of the voice I want you to imitate here's a playlist with all Sonic games in Japanese. Sonic X in Japanese is also a good reference, as well as the OVA.

Solebinku's Personal Direction:

Espio is between a tenor and bass. He's like Shadow in his more stern way of talking but has a lot of weight to it, due to being said in a character bio he has a military way of speaking. He also speaks in traditional Japanese not modern so you can hear those differences. Like how one of his lines is "Level Rising!" which is not what everyone else says. They say level up, so due to his dialect he says things in a more traditional way so you can interpret that to be more traditional English or maybe try to add a Japanese way to it. As seen by "En garde!" it's traditional. Also leave the airy ninja behind they are usually a bit more though with a bit of silence. 

So try and keep that Japanese influence and that traditional dialect in tact. 

Game Cutscenes:

https://youtube.com/playlist?list=PLhnIPa8XAn7x6g8UvkO0UaiTHtK-VBUbd&si=PqA0dj6BGoWNS7Oz

General Espio voice lines.

https://youtu.be/FiqcQjx3YeQ?si=CZb4Yq-DZvJ12ler

https://youtu.be/y_GubT66b4U?si=H3SeK2lt5D6slr1I

https://youtu.be/_aKJ-TUKqTc?si=RCvvGr7OSW_v3_Gk

If you want to learn more about the character I made a video for him on my YouTube channel:

(Did not make yet)