Power Stones are the currency behind Musashi’s basic and special skill upgrades in Onimusha: Way of the Sword, and the game does not hand them out generously. There are 53 of them scattered across Kyoto and its surrounding areas, and you need every one to finish the skill tree for the Well-Rounded trophy. The good news is that two of the three sources are repeatable, so you are never permanently short.
Quick answer: Finish each side quest the moment it appears, then re-fight cleared bosses through Boss Rematch in the Practice Ground — bosses have a high drop chance for Power Stones and can be fought as many times as you like.
Where Power Stones come from
Three pipelines feed your stock, and they are worth treating differently. Side quests are the reliable baseline, boss drops are the farm, and world chests are the finite pool you clean up before the end of the game.
| Source | Repeatable? | Notes |
|---|---|---|
| Side quests | No | Do them as soon as they unlock; they also hand out charms and other upgrade materials. |
| Boss fights | Yes | High drop chance. Re-fight bosses through the Boss Rematch menu for as many stones as you need. |
| Chests in the world | No | 53 fixed locations total, many hidden until you use Oni Power to reveal them. |
Clear side quests the moment they appear
The single most efficient habit is refusing to bank side content for later. Every optional job you accept while passing through an area pays out upgrade materials, and Power Stones show up regularly among the rewards. Jobs like What Lurks in the Shadows ask for something small — stop a contraption, kill the Genma that spawns — and take a couple of minutes each.
Doing this alongside the story also compounds. Side content unlocks charms and enhancement materials that make you stronger, which in turn makes the boss farming below far quicker.
Farm bosses through Boss Rematch
Once the finite chests and quests dry up, bosses are your infinite source. They drop Power Stones at a high rate, and the game lets you fight them again as often as you want.
Unlock the Oni Vision skills before you sweep for chests
Plenty of Power Stone chests only appear when you use Oni Power, which makes blind exploration a waste of time. Three Special Skills fix that: Oni Vision: Treasures, Oni Vision: Treasures 2, and Oni Vision: Search Range. Together they light up nearly everything worth grabbing, including equipment materials.
Those three are bought with Oni Stones, so hold your Oni Stones until all three are purchased instead of spreading them across other skills. Then get into the habit of holding L2/LT and tapping R2/RT repeatedly as you move through each area — that sweep is what surfaces the hidden chests.
Note: Power Stones and Oni Stones are separate materials that share the same Well-Rounded trophy. Farming one does not help you with the other.
The point of no return and New Game+
Free roam ends when you accept the final mission, The Clash At Rendaino. The game warns you before it starts, and you lose access to the open areas from that point. Make a manual save right there. You can also select Continue from the main menu after the credits, which drops you back before the final mission so you can keep cleaning up.
Skill upgrades carry into New Game+, so anything you buy on your first run stays bought. That matters because a single playthrough rarely yields enough material to max everything out, and Carnage difficulty is locked until you have finished the game once anyway. Treat the second run as your cleanup pass rather than trying to force completion in the first.
How to confirm you have enough
Open the skill menu and check your Power Stone count against the upgrades still greyed out. Once every basic and special skill is purchased and all 53 stones have been collected, Well-Rounded pops — assuming the Oni Stone side of the requirement is also done. If a skill still refuses to unlock despite a healthy stone count, the block is usually a missing Red Souls balance rather than a missing stone.
The practical takeaway is simple. Side quests and chests carry you through the campaign, Boss Rematch covers everything you miscounted, and nothing about Power Stones is genuinely missable as long as you keep that save before Rendaino.
