Sheriff Sinister is the boss monster of Hellspring, and is head of Seripite civilization. He is a large Seripite, dressed in Sheriff's garb and wielding a brass revolver.
Sheriff Sinister's level is very basic, designed in a minimal fashion as to facilitate the boss. It consists of a wide, open corridor in town, with buildings fencing you in on two sides. Near and within the buildings are breakable barrels and crates, which provide temporary cover. You can only enter some buildings, and their walls will defend better against the Sheriff's wrath, though he will follow you inside when not shooting.
The battle will begin in a dueling format, with the player and Sheriff starting back to back and then moving ten paces away from one another. The Sheriff will cycle between 4 attacks, though only using 2 at the start and adding the others as he takes damage. Defeating him requires using these attacks against him.
Sinister will fire off a single shot in your direction. Simply moving to the side will be enough to dodge this attack, though he will sometimes telegraph a more accurate version. This accurate version will allow him to calculate where you're headed, judging your current speed and direction. The Sheriff's eyes will flash white and he will take aim for longer when attacking this way, and freezing in place just as his eyes flash will allow you to avoid taking damage.
Sinister will unload his revolver, firing 10 shots in your general direction with reckless abandon. This attack will require a relatively long charge time, and is telegraphed by the Sheriff pointing his revolver at you with both hands, and then pulling his hat over his eyes before firing rapidly. The sheer quantity of bullets makes this attack nearly unavoidable, and to not take damage, you'll need to seek cover behind something sturdy. Sinister will then play a lengthy reload animation, leaving him vulnerable to retaliation.
Upon reaching 66% health, the Sheriff will use this attack against the player. Sinister will grab the nearest movable prop, be it a crate or barrel, and toss it at the player. When it collides with anything, it will explode violently. If no props are nearby, this attack will be cancelled.
Upon reaching 33% health, the Sheriff will behave more aggressively. The bells of the clock tower will ring and the Sheriff will look up to telegraph this attack. He will then vanish in a puff of smoke, and reappear several times, charging forwards at great speed towards the player, and then vanishing again to charge once more from another angle. The charge will come from a ring around the circle, starting in front, and then rotating 60 degrees each charge for a total of 6 charges. Upon finishing this attack, he will reappear near to the player.
Damaging Sheriff Sinister
To damage Sinister, the player has to use their environment. Mesh bags holding dynamite hang from the ceilings of buildings, and the player must draw Sinister's gunfire towards the rope suspending them to gain access to the contents of these bags. When they hit the floor, 2 or 3 of the explosives will fall free and be primed to detonate. The player must throw them at Sinister to deal damage, though if he is not attacking, he will slowly move away from the blast, and could escape their range if they are not positioned well.