SiNiSistar 2 Walkthrough — Steam Deck

SiNiSistar 2 on Steam is short enough to finish in one or two sittings, and the route is linear once you understand the act structure. Finish the swamp and the demi-human lair in Act 1, work through the village and the valley in Act 2, then enter the cathedral in Act 3 for the last stretch. The main thing that changes between runs is how many optional detours you take, because the game hides several upgrades and secret fights off the critical path.

Act 1: the Vampiric Swamp and the Demihuman Lair

After the tutorial, Hanya sends Lelia to clear abomination broodlings in the Vampiric Swamp and the Demihuman Lair. Start with the swamp: a room before its boss holds the Penetrating Arrow Magic upgrade, which lets arrows pass through enemies and hit targets behind thin walls. The swamp also introduces the leech debuff, and getting caught twice without treatment ends the run, so keep an eye on the status readout.

The Demihuman Lair follows. If you are defeated there you are taken to a prison a few maps from the boss rather than straight to a game over, which gives you a second chance. Clearing both dungeons sends you back to the church and triggers a raid on the town that you have to repel before Act 2 opens.

Act 2: the village, the valley and the detours

Act 2 widens out into Arsezon Village and the valley, and this is where the optional content piles up. A merchant on the right side of town sells a strong staff for 1,200 relics, and several villagers hand out quests that lead to new spells. The route forward needs the carpenter to repair the bridge into the valley, so talk to him as soon as the story points you there.

Detour	What it gives you	Where it is
Northeast village	Exploding Arrow Magic	North route out of the village
Wall cluster in the lair	Owl Magic (glide)	Back in the Demihuman Lair
Village quests	Relics, items and status treatment	Talk to townsfolk after the raid

The exploding arrow is the important pickup, because it strips barriers from the masked enemies and the sealed gate in the northeast village. Owl Magic is optional but turns several later platform sections into a glide instead of a fall. Head into the Innard Cave once the bridge is up; it has no goddess statue, so bring white potions to reset the dirt meter.

Act 3: the cathedral and the final stretch

Act 3 is the cathedral complex. You need the Cathedral Key from the northeast village to get inside, and the basement hideout below it is where you can take a curse that removes the Blessing of Infertility. Push up through the cathedral, then cross to Arsezon Cathedral for the closing section.

The endgame needs the Scivias Powder, a craftable item assembled from ingredients hidden in the cathedral's dining hall, library and treasure room. The library ingredient, the Staurotheca, is the easiest of the three to miss, since it sits below the first elevator rather than on the main path. Once the powder is ready, the final battle begins and the game ends shortly after.