Any way to cosplay as Ascian in game?

[Enkidoh]

As stated above, the Ascians' actual robes are not available to players, but the 'Shadowless' gear found in the level 80 ShB patch dungeon The Heroes' Gauntlet, and it's pallette-swapped 'Ktsieos' gear found in the level 86 EW main scenario dungeon Ktisis Hyperboriea are inspired by the Ascians' appearence, although the gear's look varies depending on the gear's class role.

Additionally, the Ascians' original Ancient appearence is available as the 'Sophist' glamour gear which is gained automatically during the EW main scenario when you arrive in Elpis.

But actual Ascian appearence gear is not available in the game I'm sorry to say.

[Cleretic]

As stated above, the Ascians' actual robes are not available to players, but the 'Shadowless' gear found in the level 80 ShB patch dungeon The Heroes' Gauntlet, and it's pallette-swapped 'Ktsieos' gear found in the level 86 EW main scenario dungeon Ktisis Hyperboriea are inspired by the Ascians' appearence, although the gear's look varies depending on the gear's class role.

Specifically, Shadowless Maiming is strikingly close to Elidibus' robe but as armor, while the Shadowless Scouting and Casting sets are two different directions towards 'close enough' for the black robes; Casting keeps the 'robe' vibe but loses some of the ornamentation, Scouting keeps the ornamentation at the expense of no longer being a robe. Maiming's the only one of any of those that have the red mask, though. And Ktiseos is the same outfits but in greyscale, so you lose the gold and purple accents.

I feel like they're the closest we'll ever get, because the Ascian robes... actually kinda aren't good outfits, partly intentionally. They're designed to be extremely anonymizing and unflattering so that you just can't make out a person beneath it at all, and are essentially a riff on the 1.0/ARR robes themselves which are pretty dumpy. All that, combined with the fact they're from that era in the first place and so have pretty unflattering texture work, means that the better-looking Shadowless/Ktiseos sets are probably the ones they're more inclined to give us.