Stage1 - JACK
You should easily be able to beat jack the trick is to watch out for his fire bolts, i find punching on all the boses a lot easier than kicking as you can escape quicker from there next attack by jumping away.

Stage2- Heihachi's + clones
Heihachi is easy just defend and when none of them are attacking you go for it!

Stage3- Ogre
Ogre may look scary but he's really not that hard to beat- (jus wait until you get to the last ogre). The trick here is keep running in a direction, keep constantly running and dodging ogres fire. When hes in the middle of his fire beathing attack, make your way towards him and as soon as he lands - punch him in the stomache(front on) and run away. After talking half of his life away you can then transform into devil jin and use ur hellsblast on him- make sure u lock on to him. Oh yeah you can dodge his fire bolts simply by constantly jumping.

Stage 4- Gate Keeper
Now this is actually very simple kill all he people on the stage(the one that you being on) dodge the brain looking thing as it will follow you and then keep an eye on it.It will go onto one of the stages hovering and the shield will be let down. Quickly jump onto the platforms being carefull not to fall of and jump onto the shieldless stage. Punch the metal rod in the middle and when you can no longer do any damage jump down onto the platform and make your way to the stage you began on. kll the remainng people and repeat the proccess as in the begining! after the third time of doing this there wll b no more enemies jus the miny brain things, jus go onto the shieldless stage and beat the boss!

Stage5- Ogre stage 1 and 2
Ok the first stage is easy of ogre- hes alot weaker than the one in stage three, u can easily beat him but try not to lose much health! Also dont transform into devil jin save it as you will need it for stage 2 ogre.
Ok ogre stage 2 hes mean hes lean hes a big annoying reatarded boss that can get very fustrating if you dont beat him! Now here stay close to ogre so he cant use his fire attacks.
He will sweep his tail a lot and jump up and try and stand on you but sisnce this is a meelee attack it can be blocked. After he attacks you and you block it - attack him.After its lost half its health transform into devil jin and use you hells blast and finish him off.

Good luck