Early in the game, immediately after defeating the Minotaur Boss and receiving the Chain ability, an attack dummy will appear in the save room outside the Minotaur's lair. The dummy not only gives you points toward learning new battle abilities, gained by chaining your attacks. It also gives human class experience to the weapon you are using as you attack the dummy. It gives the human class experience at the same rate you would get if you were attacking a real human class enemy.

At the Sinner's Corner save point/teleport/room and the four rooms immediately surrounding it is a phantom class enemy called the Dark Eye. After a Dark Eye is defeated it may drop a Grimoire for one of five different, rare, warlock class spells. Those spells are Solid Shock, Lightning Bolt, Fireball, Vulcan Lance, and Dark Chant. Note: These Rare Grimoires are dropped very infrequently, and some time is needed to get them.

When two items that are exactly the same are combined, the resulting item will be the same type of item, but will have higher stats. For example, if you have two identical short swords and combine them, you will lose those two short swords and get a new third short sword, with slightly higher stats.

Cast the healing spell when you are in battle mode. This will give you more HP than just healing when in normal/relaxed mode.

Throughout the game you will find training dummies near save points. These training dummies allow you to practice combos and power-up your weaponry. The locations of the training dummies are as follows.

Wine Cellar, "Blackmarket": Human dummy
Wine Cellar, "Worker's Restroom": Human dummy
Abandoned Mines B1, "The Dark Tunnel": Beast dummy
Catacombs, "Hall of Sworn Revenge": Undead dummy
City Walls North, "From Boy to Hero": Phantom dummy
City Walls South, "The Boy's Training Room": Dragon dummy
Town Center East, "Gharmes Walk": Evil dummy

Combine two Hangane Dubble-Blades to get a Hangane Halberd (Weapon)
Combine two Nodachis to get a Rune Blade (Weapon)
Combine two Khopeshes to get a Wakizashi (Weapon)
Combine an Oval and a Heater to get a Knight (Shield)