Yes, yes, I know they did one in Apocrypha. I haven't been following that, so eh. Also, basically nothing of his stats is available, and his defences are... weird.

[b]Class:[/b] Lancer
[b]Master:[/b]
[b]True Name:[/b] [url=http://en.wikipedia.org/wiki/Achilles]Achilles[/url]
[b]Gender:[/b] Male
[b]Alignment:[/b] Chaotic Neutral
[b]Appearance:[/b] [url=http://safebooru.org//images/481/6fe06cbe2cdbb43e1ffe92d98ac0a35d8010a086.jpg?482341]Behold![/url] Truly, the most beautiful warrior at Troy. Don't worry, he looks more masculine when not in disguise.
[b]Personality:[/b] Achilles is a self-centred, short-tempered, violent bruiser. He likes fighting. He likes men, and women. What he does [i]not[/i] like is people taking his things or killing his friends. Keep away from those two, and he's pretty much just overly boisterous--and rather cocky.
[b]Stats:[/b]
[list][*][b]Strength:[/b] A[/*]
[*][b]Endurance:[/b] C[/*]
[*][b]Agility:[/b] A+[/*]
[*][b]Magical Energy:[/b] C[/*]
[*][b]Luck:[/b] E[/*]
[*][b]Noble Phantasm:[/b] A++[/*][/list]
[b]Class Skills:[/b]
[list][*][i]Magic Resistance:[/i] B. Even if targeted with High Thaumaturgy or Great Rituals, Achilles is difficult to affect.[/*][/list]
[b]Personal Skills:[/b]
[list][*][i]Charisma:[/i] B. Sufficient to lead a kingdom. Worth noting is that this does not imply being any [i]good[/i] at leading people, just having the presence and beauty (see: the halo effect) to pull it off.[/*]
[*][i]Divinity:[/i] A. His mother was a nymph... and given that a god and a nymph produces a god, this seems the best rank.[/*]
[*][i]Domestic Disguise:[/i] A. So long as Achilles refrains from fighting and dresses appropriately, it is impossible to discern that he is even a Servant--though this comes at a cost, as all his abilities are considered a rank down whilst thus disguised, making a sneak attack if identified through some other means. Indeed, thus disguised, Achilles is strangely generic--if seen in different situations, connecting the maid to the Servant cannot be done. Ceases to affect anyone that sees Achilles either drop the clothing, or start fighting whilst disguised.[/*]
[*][i]Eternal Arms Mastership:[/i] A+. Retains full fighting capabilities regardless of any mental hindrance. Acknowledge as the greatest fighter of the Trojan War, Achilles' martial skills are almost without peer.[/*][/list]
[b]Noble Phantasms:[/b]
[list][*][i]Bathed in the Styx--Invulnerable Body:[/i] A++, Support. Achilles, famed for being dunked into an underworld river as an infant, is more or less impervious to harm: one ankle is the only part of his body that actually takes damage, the rest of him just absorbs the entire force of the blow (likely leading to being knocked flying from more powerful things). His insides, however, are not so impervious--so unleashing an attack through his ankle, or mouth, and into the rest of his body will do it pretty well. A direct hit with something on par with Excalibur would overwhelm even this defence... though not to the point of actually killing him.[/*]
[*][i]Retribution--Unhealing Wounds:[/i] C, Anti-Unit. Achilles spear, when used in rage, inflicts wounds that can only be healed by the spear itself... however, as a Servant, this would require Mad Enhancement, so save for the possibility of externally-imposed anger, it's just a very good spear.[/*][/list]
[b]Misc:[/b] The disguise thing is based on Odysseus resorting to trickery to get Achilles to reveal himself before the war started, the spear based on some king on the way (Telephus?) combined with Achilles' general anger at everything, and the invincibility should be obvious.