Hints
Avoid losing life
Pause game play before the last part of your health disappears. Use a healing item, and you will still have that life.
Easy experience
Find a location where enemies spawn in groups of two or three. Put a Legion on active attack mode and let them kill those same enemies for hours. This works if your Legion is strong enough, but check up every ten to fifteen minutes to make sure your health is still the same. If it has changed, check more frequently to make sure you do not die.
Let your Legions take the kills and do most of your dirty work. You will get double experience. Also, press "Force Attack" if you are in a tight spot.
For more challenging play, but better experience, when a generator keeps making monsters reappear, just stay there and kill those monsters over and over again, but don't attack the generator.
Start level 7 and go forward. Kill the opponents, then go to the generator (the one with two Babdhs around). Kill them, then destroy the generator. Go up the ramp through the gate. There will be a cliff to your left. The opponents will begin spawning. Do not go up on the cliff. Stay down, under the cliff. Opponents will continuously spawn. If you position yourself correctly, you will not get hit. This is an easy way to level up Hatred/Flawed/Blasphemy, before level 12.
On level 5, proceed to the first Boss (with the shield). Back off him and let Malice continually shoot him. It appears that they can shoot at his shield continuously and still not kill him, and without him touching you, but your experience keeps increasing.
After getting the "Map Selector", return to level 2 and complete it. Every time you finish this level, you are bound to get an "Exp Gem (L)" which you can use to give a Legion 500,000 experience points. This is very useful, as this level is very easy. It should take you less than five minutes to finish it.
To max out all your stats accept Soul Replay stage 2 repeatedly. Kill the Starving Fang that is after the first two groups of Blades before it runs away. Where it normally would be after it runs will be a Max Life Up Small.
Flawed Legion
These are the little midgets with razor fingers. Once you lock-on to a hard to-defeat metal enemy and press "Force Attack", they will surprise with how they burrow into your opponents and take their health down a by a considerable amount. They are by far the worst fighters when left in active mode, which is why they are not recommended for large group fights unless you are in a situation where your attacks are almost worthless. Note: The Flawed Legion's extra abilities and the group's unsummoned special attack are by far the most useful of any legion.
Blasphemy Legion
Their little floating bombs also turn into convenient little land mines. This legion is best used against Denu, or the metallic and shiny opponents that are impervious to your attacks.
Ultimate Legion
This is by far the game's best Legion, yet the most underdeveloped. For example, it teleports to your opponent's blind spot and basically mutilates it. When you use its unsummoned special attack, you can move through a plane of slower time. There is only one legionnaire in this crest. Also, you cannot rely on this Legion to protect. It has a reaction time, and when it attacks it leaves you very vulnerable to your foes.
Note: To get the Ultimate Legion, collect all the Thantos Chips.
Defeating Giant Trolls
Jump and attack so that you can do a spin slash at its head. That will immobilize it. Keep doing this.
Power-ups
On the stage 11, constantly explore before continuing onward. You will find plenty of power-ups.
Thantos Chips
On stage 6, there is a Thantos Chip on the far right side on the beginning. However, you have to defeat the red monster layer. Once you do that the Thantos chip will appear.
Hint Longer combos
If you want a longer combo try jumping into the air once. When coming down, you will hit your enemy once and when you hit the ground you will start your regular combo. It is still slightly longer.