The chapter below presents a number of hints that will prove useful while fighting this opponent.
Before the battle
The boss battle starts as soon as you come close to the ship. After a short cutscene, you will be transferred to the ship's deck, where you will have to fight this demon.
Before this happens, however, it is a good idea to ensure several things.
1. If you have any skillpoints connected with magic left, it is a good idea to invest them in talismans that will allow you to enchant your weapon with an elemental force. After you have unlocked the skill, use the Jutsu section in Shrine and create a shortcut to the talisman.
2. Search for all the Kodama spirits in the area, which you will leave after you win the boss battle. After you have collected all 5 of them, your number of reviving potions will increase, which may be especially important during the battle. It is also a good idea to spend your gold on blessing your potions, after which you will eliminate nearby opponents. If you are lucky, you will have several extra vials of healing items at the beginning of the battle.
3. Spend all Amrita that you have earned and level up your character, in accordance with your playing style. You can also farm several additional levels if you feel that damage you deal does not guarantee positive outcome of the battle.
4. Make sure that you have examined your weapon to the maximum extent. If you have not filled your weapon familiarity bar, it is a good idea to do that on nearby opponents. Also, find out if you have any weapons on you with higher damage multiplier. If so, it is a good idea to use it.
The battle - Stage 1
Onryoki is a unique opponent; he can be very slow only to surprise you with a sudden attack after a while. For the purposes of this battle, it is better to pick a heavier, double-handed weapon that will allow you to land 1-2 blows into the opponent's back, while not using up too much Ki for you to dash or block. The best thing to do is enchant an element into the weapon. This does not take long and each additional damage point you deal brings you closer to the second phase of the battle.
In the first phase, Onryoki performs two attacks:
1. With you facing him, he will take an overhead swing and slam the ground with the ball attached to his limb. After a while, he will perform the same action with the other limb. If the first attack deals damage to you, most probably you will also take damage from the second one, as the first one will knock you down.
After his first swing, it is best to approach his belly. He always performs his first swing with the left hand (your right). If you have been keeping your distance, dash up centrally and slightly to the left. If you are close to his trunk, chances that you will take damage are very low. At the same time, you should jump over behind his back, land 1-2 blows and start blocking, while walking slowly back (using analog sticks). If you are still high on KI, you can dash back.
2. The above is important. While you are behind the boss's back, he will take a second before he turns around to face you. At this point, the balls attached to his hands go in a swing. One of the balls goes in a wider, and the other one a narrower arch.
- If you do not get away in time, you will get yourself within the radius of the narrow swing which will knock you down, whereas the other ball will kill you.
- If you do get away, and get within the radius of the wider arch, you will be knocked down, but alive (provided you have enough health).
- If you block the first ball with your weapon, you will be knocked back to the orbit of the second ball. At this point, you will have insufficient Ki to perform a block and you will lose a half of your full health.
- If you get away to the orbit of the second ball and block it, you will be knocked back. At that point, get away into medium distance and wait for your Ki to regenerate.
It should be pointed out that the second ball (i.e. the one that goes over the wider arch), remains in the air for a moment, after the swing. Then, it drops to the ground. If you happen to be standing in that spot, you will probably die.
The first stage lasts until you bring the violet bar under the opponent's health bar down. At that point Onryoki's chains break and he starts using different attacks.
The battle - Stage 2
After Onryoki's chains break, he will start moving much faster. At this point, he will start implementing one of the two tactics: he will either try to shorten the distance to deal damage, or he will be hurling the balls at you. In this stage, the opponent will be opening portals to Yokai Realm. Situations at which this may happen have been provided below, but keep in mind that there can only be 2 portals opened at the same time. As soon as another one appears, one of the opened ones will disappear.
1. When you are at a considerable distance from the opponent, he will approach the balls. You can perform a quick ranged attack at this point, but be careful because the boss will quickly hurl the ball at you, after he grabs it. The ball's hitbox seems to be a bit wider on the left, which makes it easier to evade to the right. Still, the differences are miniscule. Remember to dodge at the moment at which Onryoki takes a swing, and you will always succeed. As soon as you spot him heading for the balls, stand in the spot that will not block your dodge and, what's most important, do not stand near the ship's wall. Onryoki will hurl both of the balls at you and head for short range, in an attempt to get the balls again.
2. While at close range, the boss's attack can be unpredictable, so keep your eyes on him.
- While you stand in one spot, Onryoki will jump at you with an overhead attack with clasped hands. The spot in which he drops to the ground will be branded with Yokai Realm.
- While you are moving around, he may perform a series of strange swings with his hands and drop onto the spot that you are standing in. After the drop, the spot will be branded as Yokai Realm.
- He can perform a ground slam with his right fist, in the spot he is standing in.
- He can perform a swing with his right hand.
At this stage, it is easy to hit him on the back, if only you dodge the blow. However, the opponent may perform a swift, unmarked left-hand blow behind the back, which may be lethal.
The boss will keep repeating the same set of attacks until he is killed. It is a good idea to use shurikens, gunpowder bombs and enchantment of the weapon with fire. Also, it is a good idea to start the battle with your Living Weapon all charged up and use the skill when you are cornered.
Finally, the opponent will fall to the ground. Collect the items that he drops and cross the portal to continue the campaign.