I can see many people are having trouble in Sinjid .Here I have made a In-depth walkthrough for Sinjid.[WARNING:SPOILERS]I wont reveal ANY story here except the name of places and some names of persons and a betrayal.
About my knowledge in this game:I have finished the game on hard difficulty with warrior and normal on assassin and easy on priest.
This guide focuses on the toughest bosses.
General Tips:a)Try to finish all the side-quests
b)Talk to Scout Eri before starting a mission because she has useful information.
c)Explore all areas.
d)Once you have rescued Shigeru,Don't waste the shadow gem he gives on your current equipment.Save it and use it on your final set of equipment.
e)Once you have unlocked the Fallen Village,talk to the food vendor and he gives a quest for you to obtain exotic spices for him.buy it from the dutch trader in emerald temple and give him that.Now he sells food items and empty bottles.Fill your inventory's remaining space with the empty bottles except one space.Each space holds about 5 bottles.After this,head to the rightmost side of the fallen village.You will see a well there.This well contains ELIXIR OF HEALING!Fill your empty bottles with this and sell it to the food vendor.Each bottle is worth about 33 yen.It is a 31 yen profit for EACH BOTTLE.Use this to buy weapons and armor from The Fallen Village vendors.
Now to the Bosses:
1)Warlord Niroshi:This guy is pretty tough in hard difficulty.Use slam whenever available to interrupt summoning of dead samurais.Keep the pressure on him.Kill the fallen warriors first because they deal high damage if grouped.Kill them to avoid being overwhelmed.
2)Lady Akari: She is really tough for warrior on hard difficulty.By now you should have heavy armor skill to get another chance.Heavy armor skill at level 1 reduces taken damage by 35%.Eat a Vitality boost food item before fighting.Dodge her fireballs carefully.You have 2 chances,Jump over it or duck.Ducking is invulnerable to Akari's balls when you are at a straight angle to her.Her fire jailor ability is annoying.Every 5 seconds(i think so)she has the ability to lock you in air.Use slam to interrupt the fireball casting.Good luck!
3)Lord Dai'Jin :He is a tricky boss.You should follow an attack pattern to defeat him.His armor regenerates by the number of attacks you attack him while his armor is activated. EG .you hit him 3 times while his armor is activated,then it regenerates 27 health per second.His armor activates for every hit.Armor activated lasts for 3 seconds.Never use blade-storm on him because it consists of more than 1 hit.Use your most powerful 1 hit attack available.Rinse and repeat till you win.
4)Ryota the Sly:Quite a simple boss.Hard on hard difficulty.You can dodge the poison arrow.Just after it hits you run and escape the poison cloud which follows.He has a continuous healing passive skill,so you have to keep the pressure on him.Hit him with all you got.
5)Lord Takeshi: This one is really tough.It took me millions of tries to beat him.The poison cloud should be dodged immediately.Interrupt it or RUN!It stuns you+Damages you.He also uses a Kunai to pull you towards him.He has a healing ring which heals him during battle continuously.Use Doom Blade whenever possible and strike him with your BEST attacks.Upgrade concentrated brew to the max level.Keep trying.Don't lose heart.After this fight,you will be level 15 and Ultimate Ability is unlocked.Choose Deadly charge because it combined with brutal advantage can destroy health.See here:
6)Warlord Asura: He is tough on hard.His attacks and moves maybe simple but he is too difficult.He has a charge attack which totally destroys you.It deals roughly 1000 damage.It also has a increased range than normal attacks.So it you jump while the charging bar is above half,you are sure to get hit.So when you see him charging,just run away OR interrupt.If you are too late,then block the attack to reduce damage to an extent.His next move is to get healed for huge amounts(about 500 per SECOND).But he gets stunned during this time.Use doomblade and hit with all you have.This move also charges before activating so try to interrupt.Always save slam attack to interrupt important moves like these.Asura can be defeated.Good luck.
Note:After this point,the Fallen Village is unlocked so follow tip number 5(E) to get as much money you want to buy armor and weapons.Use the 2 shadow gems you have been saving.(1 is given by shigeru and the other is found on the top of the emerald tower in emerald temple which taro mentions)
7)Lord Tetsou:He is pretty tough.He has 2 main moves and a lot of health.His first attack is to shoot a moon-blade.This one deals INSANE damage(About 1600) and is homing.You can dodge it by jumping on top of it or run till the end of the room and then wall jump.If you got caught,block to reduce as much damage as you can.Interrupt it if you can as it is a charging move.Another one is to heal constantly like Asura.He gets stunned here too.Try sometimes and you will win because you have the best equipment available.After this fight when you come out you see a chest.Open it and give the doll inside to Pazu the doll collector in Fallen Village to get a valuable artifact.(secret)
8)Ichisan Retainer:The Mid-boss of The Ichisan Castle.He has one annoying move and a lot of health.This move is to regenerate ALL of his health.It has a long casting time.So,just while it is about to end use slam to interrupt.Otherwise easy.
9)Kasumi:She was defeated by me in my first try.Her attacks are quite the same as an assassin.Becoming invisible,back stabbing and all that.Not that tough.Just want to mention.To think that she was the best shinobi in the land...
It is time for the final fray:The Shiroda Fortress
It has 4 tough enemies:1)Mistwalkers
2)Shiroda Priest
3)Lady Shiori
And finally Lord Kazuro
1)Mistwalkers:Pretty tough if you aren't alert.Never let them attack you because their attack is devastating.Their poison can kill a priest and a assassin in seconds.But warrior can escape if they have heavy armor.Use all of your moves and kill them before they get a chance to attack.
2)Shiroda Priest: She is a normal enemy but as powerful as a boss with destructive moves.You encounter her twice.Once after defeating Shiori and next before Kazuro along with a Shiroda worker(This is where I lost lots of times)She has 4 moves.First is to summon a shadow guard(remember Niroshi?).They can be a tank for her and annoying when trying to run.Second,she heals herself for a small amount but very quickly.Third is to summon a Moon Blade(Remember Tetsuo?) which does little more damage than Tetsuo's moon blade.The last is a purple attack which takes away all of your focus.Dodge this somehow.It flies in a straight way.So it is easy to dodge.Try your best.She is very hard on hard difficulty.Try to kill the shadow guards when free because they may overwhelm you.Use the same method to dodge the moon blade.Healing doesn't matter.She also has an invincible shield for some time.Good luck
3)Lady Shiori:Very feared boss but she lives up to her name.Her 2 attacks are:1)She flies in the air and shoots poison bolts at you.Start from the bottom of her and run in either direction to dodge all the bolts.Even 3 or 4 hits,you are dead.For assassin,just throw a smoke bomb and stand under it.2)The gaze.The deadly gaze.This paralyzes you and damages you a lot IF YOU DON'T TURN AWAY.Just as she is about to end casting turn away or interrupt using Slam(as i said before,save it for interrupting).If you are at a distance,turn away and wait till you get hit by a small amount(because you are turning away).After that continue.She took me a few tries then I'm done.
4)Lord Kazuro:Here your Struggle ends.He is an INSANELY TOUGH BOSS on hard difficulty.He does a lot of moves and attacks.His first move is similar to the warrior's shock wave.But this one is is violet colour.It stuns you for long and damages you.Just run away it as he starts to cast.His second move is to fly in the air and locks himself their for a time.During this time he summons a exact clone of you with EVERY MOVE YOU HAVE.When you defeat that clone,he drops back.He also has a healing move similar to Warlord Asura.He stuns himself and heals for huge amounts.He has about 20000 health on hard difficulty.You have to be very careful and make sure that you don't get hit by the shock wave.Kill the clone as soon as you can.Use doom blade when he heals.Good luck warrior.Don't give up after coming this long.