Doppler Soto or Chancellor Doppler
(a.k.a. Kommisar Krell)

The evil leader of the Doppler Elite Corps. He was present at the launching of the original Promete project. He was behind the brainwashing of Colonel Ichimonji and sabotage of the project. He will stop at nothing to prevent Dr. Oedo from reaching Promete. He sends Mecha-Satans to destroy Jasdam and all who oppose him are either eliminated or fitted with a steel mask and turned into a mindless slave.

*This the only anime villian I've ever heard of with the title "Soto" other than Desler (Desslok) of Space Battleship Yamato fame. I believe it to be a variation of "fuhrer." If anyone knows a more accurate translation of "Soto" please email me.

Doppler seems to be of a different humanoid race than that of Earth humans. I would know for sure but it is never mentioned in Force Five what his race actually is. And, since I'm only partially fluent in Japanese I can not determine if it is ever mentioned in the original series either... This is obviously a take on Nazi-ism with the sinister Doppler wanting to conquer Promete for himself and only people of his own "master race" or "Selected Ones" can bask in this glory.

Say what you want about Doppler Soto... But he plays a mean and sinister organ! >:)

He is Doppler's right hand man. He's the brains behind the creation of the Doppler Mecha-Satans. He designed the steel "slave" mask that Captain Dan now wears. He never has any remorse or redeeming qualities for a villian. Yup, he's as  nasty as they come! Even More so than Doppler himself!

Commander Gudon was the first Mecha-Satan team leader. He fights the Danguard Ace and Captain Dan in the very early episodes of the series. He lasts until episode 27. In every battle against Danguard Ace, he managed to slip away in an escape ship from his doomed Mecha-Satan. He met his fate in Mecha-Satan "Yazilar" when he shot down Jet Joe (who was piloting a stolen Harken fighter). Danguard Ace avenged Joe's death by destroying Yazilar and Gudon's escape ship! This time, Gudon wasn't so lucky...

*As you can see in this animated .gif of Gudon, Doppler felt that Gudon spent more time grooming his mustache than concentrating on destroying Danguard Ace. Hence, the very quick and close shave. Courtesy of Chancellor Doppler! :)

Chief Engineer/mechanic Prague
(a.k.a. Chief Engineer Flog)

Prague is the chief engineer of all Mecha-Satans and Doppler's flagship: Planestar. Prague was loyal to Doppler almost until the end of the series. He detected that Doppler's trust in others (especially Earthers, note the non-pointed ears on Prague) was growing very thin. He felt that Doppler's obsession with destroying Jasdam was interfering with the ultimate goal, Promete. Prague planned to defect in Mecha-Satan "Gun Dog." But his plan was thwarted by Doppler as one of Harken's men was sent with him to make sure he stayed loyal. One of Prague's men killed the Harken soldier out of loyalty to Prague but would NOT join Jasdam. This unfortunatly resulted in a Kamikaze attempt at Danguard Ace that only suceeded in killing themselves off and leaving Danguard mildly damaged....

Commander Paul
(a.k.a. Sub-leader Saul)

Commander Paul suceeded Cmdr. Gudon in being the Mecha-Satan team leader (if only for 1 episode...). Paul was insulted by Tony Harken's snyde remarks (and a shot of Tony's whip) about the Mecha-Satan team being a joke compared to the Harken Elite Squadron. Paul begged Vice-Chancellor Hechi redemption of his honor and the late Gudon's by requesting an attack in Mecha-Satan "Dytanker" (a.k.a. the Boraton Robot) against Danguard Ace.

*I loved the accent he had in the Force Five version when he begged Dr. Monicle to attack. "Harken has called my Mecha-Satan team inferior and something called 'Big Bozos.' Please Dr."