Boss: The Butcher
Hit Points: 50
Damage: 6-12
Reward: The Butcher's Cleaver (+10 to Strength, 4-24 Damage, Durability = 10)
Tip: Finally, a monster that can actually wound you! Get ready for a mass beating unless you have a good shield and high AC. I would suggest going through the first levels a few times and getting your character to a higher level too. Also, using a bear weapon can make the job much easier.

Reward: Ring of Truth (+10 Hit Points, Absorbs 1 point damage per hit, Resist All 10%)
Tip: Try not to overwhelm yourself with enemies. Step forward cautiously, and fall back to let them come to you one by one.

Boss: Skeleton King
Hit Points: 60
Damage: 6-16
Resistance to Fire and Lightning
Immune to Non-Fire and Lightning Magic, except for Stone Curse and Holy Bolt
Reward: The Undead Crown (Armor Class = 8, Life Stealing +5%)
Tip: You had better stock up on the mana potions for all the skeletons, because there sure is a lot of them. Blunt weapons like a mace, morning star, or hammer are effective as well.

Boss: Gharbad the Weak
Hit Points: 120
Damage: 8-16
Reward: Random magical item
Tip: Don't sweat it, this guy very weak like the name implies. The first time I saw him, I had an inferno staff and melted him right in his tracks. As the sorcerer said it best, "I'm not impressed."

Boss: Snotspill
Hit Points: 220
Damage: 10-18
Resistance to lightning
Reward: Harlequin Crest, if the sign is given to Ogden (+2 to all stats, +7 to Hit Points, +7 to Mana, -3 to Armor Class, -1 to Damage Received)
Tip: Snotspill and his many followers guard the way down to level five. Long range spells are effective, as are good swords.

Reward: Empyrean Band (+2 to all stats, +20% to Light radius, Fast hit recovery, Absorbs trap damage)
Tip: The rock on the fifth level is heavily guarded by monsters. Once acquired, take it to Griswald for the magical ring.

Reward: Arkaine's Valor(Splint Mail, +25 to Armor Class, +10 to Vitality, Absorbs 3 points damage per hit received, Fastest hit recovery)
Tip: Prepare to fight plenty of demons. Use the highest level spells of Firebolt and Charged Bolt. Warriors and Rogues will want to close the distance so the demons won't charge.

Reward: Guardian Spell
Tip: Again, there are many demons to battle. Conserve mana by not firing until the demons are up close, and use edged weapons on them. Blunt weapons would be useful on the skeletons.

Reward: Optic Amulet (+20% to Light Radius, +20% to Resist Lightning, Absorbs one point of damage per hit, +5 to Magic)
Tip: When fighting the Hidden hand to hand, left click and wait for them to reappear, and left click to attack again.

Boss: Zhar the Mad
Hit Points: 360
Damage: 16-40
Resistance to Fire and Lightning
Immune to other Magic (except Stone Curse)
Reward: ()
Tip: Long ranged spells work well against Zhar. For hand to hand combat, left click to swing once and wait for him to reappear, and left click again to swing at him. Repeat this process until he is dead.

Reward: Spectral Elixir(+3 to all Attributes)
Tip: On the ninth level, you must pick the largest mushroom in a patch and give it to Adria, and return to the 9th floor and kill a demon to get its brain. Take this to Pepin to get the Elixir.

Boss: Lachdanan
Hit Points: 500
Reward: Veil of Steel (+50% to Resist All, +60% to Armor Class, -30 to Mana, +15 to Strength, +15 to Vitality, -20% to Light Radius)
Tip: He is not an enemy. All you do is find the golden elixir that he wants on the 15th level to get the Veil of Steel.

Reward: Griswold's Edge (Fire Hit 1 to 10, +25 to Hit, Faster Attack, Knocks back monster, +20 to Mana, -20 to Hit Points)
Tip: Return the anvil to Griswold so that he can create a powerful blade. It is located somewhere on the 10th level.
 
 

Boss: Warlord of Blood
Hit Points: 850
Damage: 35-50
Immune to Fire, Lightning, and other Magic
Reward: random Magical item and access to the 14th level
Tip: This guy has some powerful armor, so one must first lure his followers away and take care of them. Then arm themselves with the best armor and weapons and fight hand to hand. Spells won't be of any help here.

Bosses: Archbishop Lazarus, Red Vex, and Black Jade
Lazarus' Hit Points: 600
Lazarus' Damage: 30-50
Red Vex and Black Jade's Hit Points: 400
Red Vex and Black Jade's Damage: 30-50
Reward: a chance to kill Diablo and 3 random magical items.
Tip: Hand to hand fighting can be a little tricky. Hit him once and wait for him to teleport and respawn elsewhere, and attack him once again. Continue the pattern to take him. Sorcerers and Rogues would be best served using long range attacks, targeting at the location to which he teleports.

Boss: Diablo
Hit Points: 833
Damage: 30-60
Resistance to Fire, Lightning, and other Magic
Immune to Stone Curse
Reward: You emerge victorious and beat the game.
Tip: I usually cast mana shield, fill the belt with full rejuvenation potions, and take on Diablo face to face. His short range attack is less powerful than his magic. Also, if you have any Apocalypse scrolls or charges, you can wound him from the other side of the wall before opening it. Also, you can phase into the room with him and attack awhile, and when you start to lose, phase out and take a breather.