The character in the image features a multi-eyed figure - specifically six of 'could be' eye features. Master Yi has seven "eyes" (goggles), whilst Jax has six of this feature. I think it is more likely to be Jax than Master Yi judging from the image alone.
Default uses a lampost.
Temple uses a double-edged poleaxe.
Vandal uses a nailed club of wood.
Pax uses a bamboo staff.
Jaximus uses another double-edged poleaxe.
Nemesis uses a morningstar.
A blade addition to these weapons is not a bad idea.
They all have one thing in common, they are weapons stuck to poles or are long ranged melee weapons. Maybe the weapon has hidden features, like an extended handle to allow Jax to use it two-handed/long-ranged?
What works:
• "Multi-eyed." Jax has six "eyes" just as the character in the PROJECT image.
• He also wears headgear that has the tail feature.
• He holds the title of "Grandmaster at Arms". His lore expands upon that with mentioning that he has mastered the use of every weapon available and this could include the style of weapon that the Hyperlight Blade is.
What doesn't work:
• "Alpha" isn't something I'd personally use to reference the identity of Jax. Alpha of all weapon masters? Maybe.
• "Multi-target" would only reference Jax's counter-strike ability, all of his other abilities are either a feature for himself or for a single target. I wouldn't use this to describe a characteristic of Jax's identity.

What works:
• Default uses a bladed weapon.
• "Multi-eyed."
• Double-edged nature of the weapon may reference his Double Strike passive.
• "Precision balance", sounds like Master Yi's philosophy.
• "Alpha" and "multi-target" seems like his Q ability, Alpha Strike.
What doesn't work:
• He has seven goggles/"eyes", the character has six.
• The main blade of Hyperlight Blade is not long enough for standard sword use. Unless it is intended to be a complete visual rework.
The weapon description, heavily favours Jax; highly unlikely, Rengar or Renekton.
However the character description favours Master Yi, quite heavily.
I can't really decide, I would go with a chance:
48% Jax skin.
37% Master Yi skin.
12% Other Champion skin.
3% New champion.