Not much is known about Sulik, apart from what little he tells to the Chosen One. He says that he is from a primitive village located by the 'Great Salt Water' and has come in search of Kurisu, his sister who he thought was captured by slavers.
The large bone driven through his nose he calls 'Grampy Bone'. It is connected to the tribal lore of his family and village; through it he is able to speak to his grandfather and other important dead spirits of his tribe, who give him advice, cryptic as it may be.
If asked about his sister, Sulik says she "gone trading another village and never come back". Upon further questioning, he divulged that when he investigated, he found "One survivor. Dude was in bad shape. Said evil warriors with magic torches came. Fire would lick tribe warriors and they'd go to the spirit. [...] The evil warriors tied up the rest and took off. Sis with 'em. Fren, we be find her or dying trying." The description is remarkably similar to that of Hakunin's upon the assault on Arroyo by Enclave soldiers. It is possible that this village was raided by the Enclave as well, snatching captives for experimentation with the weaponized FEV.
At the beginning, Sulik requests that the Chosen One help him find his sister; the trail leads to the slaver Metzger, but she is nowhere to be found there.
The Chosen One can ask Sulik to "consult the spirits" for advice on their current quests and their current location. Sulik will provide poetic yet nebulous phrases, though they are not really actual advice they do provide insight. For example, when the quest to return Anna's locket is active, Sulik says of the ghost "Hey! They say another bonespirit's here. Needs help." Furthermore, when searching for Vault 13 and in NCR he says "What you seek is not here. The path to that is". Some of this advice is not place- or quest-dependent, and can be heard anywhere, although they are more philosophical than useful.
Sulik will disband or refuse to join the Chosen based on the following:
Sulik will even join a low Intelligence character. At first, he will make fun of the Chosen One, talk about a big hole in their head, but can if pestered a bit. The Chosen must have $350 when attempting to recruit Sulik, as there is only one shot at recruiting him through the dialogue combinations. Either way, Sulik makes a poor recruit due to communication problems (e.g. he cannot be ordered to wait or put away his weapon through dialogue).
Sulik prefers to fight with melee weapons, and joins the Chosen with a sledgehammer. While the sledgehammer doesn't do great damage, he will knock enemies down and back with it, tying up attackers and costing them action points. At his maximum level he has 12 Action Points, the highest of all recruitable non-player companions that can use firearms. At this point, if given a super sledge Sulik can attack four times a round if he does not knock the opponent back at first. But, when range is an important issue, his high Action Points are best utilized by giving him a .223 pistol, allowing up to two attacks per round, and enough extra points to reload or move a small distance. 14mm and .223 pistols are the only non-SMG pistols Sulik can use, as NPCs are able to use weapons they have animation frames for, and the mentioned pistols use SMG frames. This also means that although Sulik has skills in throwing, he cannot throw weaponry because he does not have the frames for them. When armed with SMGs, Sulik is a powerful ally in combat, able to use top-tier guns such as an H&K G11E and H&K P90c to devastating effect, but one should be wary that his bursts are quite hazardous to oneself and civilians.
As a human companion, Sulik can wear Power armor and its variants.
Primary leveling skill: Melee Weapons.
Leveling skills: Small Guns, Unarmed, Throwing, Outdoorsman.
Sulik was designed by Fallout 2 lead designer Matt Norton.
Sulik returned to the primitive tribe for a few moons (months) after breaking paths with the Chosen One, then headed east in search of his sister. It is left open for future games and fan opinion to close out Sulik's story and decide whether the story of Kurisu, told in Van Buren, is part of it.
In official, unmodded Fallout 2, Sulik never levels up to Stage 6, though his Stage 6 data is present in the game files. It is unclear whether this is due to faulty programming or a deliberate decision by the developers to leave the content out.