Char Aznable ( Gundam , Gundam Z , Gundam ZZ , Gundam : Char's Counterattack )
The first masked dood of the Gundam series.
In the first Mobile Suit , he came into conflict with the protoganist , Amuro Ray , several times in a row with his red painted custom issue of Mobile Suits. Ranging from a ZAKU II to a Gelgoog Custom.
His feats had earned him the title of the "Red Comet" and other than being a superior pilot , his philosophy , wisdom and charisma can be seen in Char's Counterattack.
Whilst not "evil" , his ways can be extreme and his philosophy had stood the test of time.
His easily the best antagonist the Gundam series have ever seen.
Rau le Creuset ( Gundam Seed )
He looks like Char , no?
However - unlike Char , his ideas are extreme and his hubris is undeniable - their goals , intentions , will and philosophy are worlds apart.
If Char can be considered a saviour - Creuset is the pure incarnation of destruction.
However , like Char , his skills with a Mobile Suit is undeniable and despite the fact that he does not carry the edge in battle as a Coordinator does , he have placed heavy strain on the pilot of the Strike unit.
His other fellow clones are no match to his wickedness , ideals and piloting skills.
Carozzo "Iron Mask" Ronah ( Gundam F91 )
Well , here we have another sicko whom intends to wipe the Earth clean of it's populace. Boy , we have Axis , nuclear satellites and... mechanic bugs? What's next , Sunrise?
Iron Mask Ronah is easily the most dangerous antagonist Gundam history have to face. Whilst his philosophy and wisdom is not that of Char Aznable's - his ability as a pilot is lethal.
His physically superior - or rather , he have superhuman strength and his telekinetic abilities can be more effective than any firearm.
If it's superior pilots we're talking about , can anyone outmatch this nutty masked man?
Neo Lorrnoke ( Gundam Seed Destiny )
Who would've thought that twiddling around someone's brains would turn them into a ruthless leader.
Well , the true identity of Neo Lorrnoke would be a bit spoiler-ish so I'll leave it at that.
Zechs Marquise ( Gundam Wing / Endless Waltz )
Zechs is a masked man with a bit of a background and like Char , he ain't too evil - or rather , his the one closest to peace whilst having an ideal of his own.
Zechs is shown to have... well , remarkable piloting skills and is shown to attract loyalty of the people around him and the tolerance of those whom are his higher-ups.
He is not proud - but he does not deny his skills either - how he monotonously admits his own skills with neither pride nor humility makes him a rather unique character.
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Cronicle Asher ( V Gundam )
Not sure whether I should add him to be honest.
He have a mask but... ehh , let's just say it's more like some flimsy cloth covering up his face than the usual masks you see in Gundam antagonists.
Asher is a capable pilot , being able to put up a fight and even a form of rivalry with Uso Ewwin whom is piloting a Gundam and as a soldier , he is effective and somewhat concerned about the safety of regular citizens.
Schwarz Bruder ( G Gundam )
Did I spell it right? :X
Anyways , this ninja dude pilots the Shadow Gundam / Gundam Spiegel and he is one of the more talented pilots in the Mobile Gundam Fighter series.
Since it's G Gundam we're talking about , I don't really need to go into the "personality and ideal" thing.
Graham Aker / Mr. Bushido ( Gundam 00 )
Stubborn but fairly charismatic. Graham Aker proves to be an exceptional pilot as he is able to put up a fight with a Gundam using only a lightly armored Flag.
His pretty much a fighting nut since his only purpose is to fight against the Gundam units as he finds himself obsessed with them ever since he got his arse kicked by the Celestial Being Gundam units.
I swear these masked dudes are lacking in ideals and philosophy ever since the appearance of Char.
Full Frontal ( Gundam Unicorn )
Char Aznable with Gym Ghingham's hairdo ( Turn A Gundam )
His also known as the "Second Coming of Char"
Whilst a clone of Char , he is not exactly HIM in question. ( Even the face looks slightly different )
Full Frontal recognises the fact that he is a clone and he does indeed bear great wisdom - not to mention skills like the person he was based off.
But his beliefs , idealism and philosophy is slightly different - in a way , his more manipulative. A slight difference in his thoughts had made this man different from Char - though the two have a few things in common. Their wisdom , their strength in their philosophies and their skill as Mobile Suit pilots.
Full Frontal - too - have said many memorable lines. He had also once said that he would become Char if the people will him so - making him and Char alike look like the very core and existence - the very philosophy of the organization of Zeon.
Still , the fluffy hair does put me off a little.