Shun is a very handsome, even called "pretty" young man. He's on the shorter side which, coupled with long green hair and general mannerisms, makes him come off as somewhat effeminate. He is kind and polite first and foremost, and can be moved to tears fairly easily. If wearing his cloth, he has two metal chains wrapped around either of his forearms as weapons, as well as pink plate armor. The armor varies in appearance depending on which form his cloth is in, (found in his gallery) but is generally always some variation of pink, usually without covering his entire body.

(*)In canon he's 13, but given that it's a shonen manga/anime and he's literally a child soldier, I play him as anywhere from 15-17 given his maturity level.

Shun is a Saint of Athena, a soldier trained from childhood to wield a power called "Cosmos" and fight using an armor called "cloth" with power based upon one of the Greek constellations. For Shun this is the Andromeda constellation, and Shun embodies many of the features of the myth behind the constellation. Shun is very self sacrificing, kind and gentle. In most scenarios Shun will defend until he is given absolutely no other choice, and even then he prefers to do as little damage as he can to his opponents. He would give his life in defense of the goddess Athena or any of his comrades without hesitation, even though his rank as a Saint is the lowest it can be, "Bronze".

Shun is emotional, and is not ashamed to openly show how he feels. He cries easily and feels empathy for those he meets whether they be friend or foe. Even when mocked for being a "crybaby" or facing his own brother trying to kill him, Shun stays true to himself and chooses to live his life with kindness. In the case of his brother, Shun is incredibly fond of him. The older boy had taken Shun's place in a harsh training environment, very possibly saving his life. Even when Ikki returned to Japan jaded and full of hatred, Shun had faith that the kind brother he remembered from his childhood was still there and refused to fight him until absolutely necessary.

(**)Shun is considered to be the "purest soul" on Earth of his lifetime, and as such was chosen to be the vessel for the god Hades' soul. This makes him the human incarnation of the god, in the same way that Saori is Athena and Julian is Poseidon.

Despite his pacifistic nature, Shun is shown to be incredibly strong when he finally does fight. He has a variety of techniques making use of both his Nebula Chain weapon and also his cosmos itself. A list of his techniques as well as a breakdown of the concept of "Cosmos" can be found here.

As for inventory? Chances are Shun is either in his Cloth or is carrying it in its Cloth Box. Said Cloth Box is the size of a very large back pack (see this image for an idea). He is able to use the Nebula Chain with the Cloth inside the box, or any other portion of the Cloth individually, but given the properties of the Andromeda Cloth he'd be unlikely to use anything but the chain separately from the rest.

If I'm playing him pre-Hades saga, he would also have a necklace. This pendant binds his body with the soul of Hades, and it would appear that losing it strengthens Hades' hold over Shun's body.