After defeating Dragon Worm, continue on through the forest and you will come to a gate that tells you to destroy the dragon to the left in order to pass. The Pure Land’s path is easy to navigate, so I’ll just cover the bosses you’ll encounter.
Snow Dragon
Have the sprite cast Exploder and other fire magic. You may also want the girl to cast her fire magic if you aren’t using a lot of her MP for healing. The Snow Dragon’s ice attacks cause a lot of damage so attack aggressively. It likes to charge back and forth across the battlefield but it can be hit with charged attacks when it stops to rest.
Axe Beak
Axe Beak is very hard to hit with weapons, so have the sprite cast Freeze on it. Axe Beak will jump back and forth between 2 platforms; you need to be quick in order to hit it.
Red Dragon
Red Dragon’s fire breath causes a lot of damage. Have the sprite cast Freeze and have the girl heal. It is easier to attack with weapons when you are above the dragon on the screen. It moves similarly to the Snow Dragon so you can use what you learned there to beat the Red Dragon here.
Thunder Gigas
Thunder Gigas fights like the Frost and Fire Gigas, except it casts Thunder. Have the sprite cast Earth Slide and attack with weapons when the Thunder Gigas isn’t floating around in particles. It spends most of the battle in particle form so you need to time your attacks very carefully.
Blue Dragon
Blue Dragon is very quick and flies across the screen a lot. Compared to the previous 2 dragons, it is very aggressive and will stop only for a brief moment. It will also casts spells rapidly so don't give it time to move between your magic attacks. Draining its MP entirely will be very helpful here. Have the Sprite cast Earth Slide and attack with weapons when it pauses momentarily between charges.
After defeating the Blue Dragon, go past the gate and you will see the Mana Tree from a cliff. Just then, Thanatos uses the Mana Fortress to destroy the Mana Tree. You regain consciousness lying next to the destroyed tree. The Mana Tree will then begin to tell you a story of the boy’s past and family. The Mana Tree will then release all of the seed’s power. The seal on the Mana Fortress is now gone.
The path through the fortress is fairly linear. You can hack away green crystals that block your way with the axe. You may want to spend some time leveling here. The enemies in the Mana Fortress will occasionally drop the best armor in the game which can't be bought at any shop.
At your first intersection, use the whip to cross the gap instead of walking left. Hack through the green crystals.
Buffy
Buffy fights similar to Vampire so attack only when its cape is open. Have the girl cast Lucent Beam. The sprite's spells are a decent substitute if the girl's Lucent Beam is not leveled up. It will sometimes cast Wall on itself so be sure to dispel it as soon as possible.
Step on the green tile on the north part of the room after defeating Buffy. The next room is rather large and confusing because it loops back around. Head north and use the whip to cross the gaps. After you can't go up anymore, start heading to the right and you will eventually come to a switch that will create a bridge. Cross the bridge and step on another green switch.
Dread Slime
This fight will be a lot like the encounter with Lime Slime except it will get bigger as it takes more damage, making it difficult to hit with weapons towards the end. Have sprite case Dark Force on it and use charged weapon attacks. If you get stuck in it as it gets larger, you may have to rely only on attack magic.
You may want to leave the fortress and save at this point. Continue making your way through the fortress and you will come to a green teleportation tile that will bring you to Thanatos. Before continuing, this is your last chance to level up.
Dark Lich
Have the girl cast Lucent Beam on Dark Lich. If her magic isn't leveled up you can rely on the sprite's magic. Landing attacks with weapons is difficult so you will likely want to try and keep casting spells on him so he will have a difficult time making attacks of his own.
Afterwards, the fortress begins to shake.and the sprite tells everyone they need to get out of there.
Mana Beast
To damage the Mana Beast, you need to cast the Mana Magic spell from both the girl and the sprite on the person holding the Mana Sword. It's best to have the boy equipped with the sword. Once both spells have been cast, you will have the mana sword until one or both of the magics fade. The easiest way to tell if you have the sword active is to look at its appearance - the Mana Sword will be a blue color. The mana beast will go to the back of the room and make a few charges against you. It will then approach the platform and that is when you want to hit it with a charged attack from the Mana Sword. Heal up during the first charge and then cast the mana magic during the second charge. That way you will be ready when the Mana Beast approaches the platform.
Congratulations!