Liches are undead sorcerors who have found a way to defy death by magical means. In the Seiken Densetsu series they are always depicted as the upper half of a skeleton which floats around. In other games Liches are usually bound to some magical item which holds their actual soul, and upon destroying that item the lich will cease to exist. In the Seiken Densetsu series all it takes is a bunch of damage to be away with them. They are always associated with evil.
The Lich is found in the Lich Cave north of the Crystal Desert. It guards the magical spell NUKE. During the battle it will fly around in a figure eight pattern shooting skulls at you. Occasionally it will fly off screen and then reappear on the opposite side.
Thanatos – The Dark Lich
The Dark Lich in SoM looks very similar to the one found in Final Fantasy Adventure. The Dark Lich is actually Thanatos and is found in the Mana Fortress. Thanatos usually keeps his spirit inside a host body, but when Dyluck resisted him he was forced to come out and face the Heroes in his true form. He fights using multitudes of magical spells, and even if he runs out of MP he can continue to hit your characters with various Glares. Throughout the battle he will switch from his normal floating form and a form where his hands appear protruding from the ground. During this form he will clench his fists to have his hands exude a magical force. Sometimes his head will pop up during this form and you can attack it. When The Dark Lich is defeated the seal on Dryad’s Mana Magic will be lifted.
The Marked Mage – The Dark Lich
The Dark Lich in SD3 is the final boss in Kevin or Carlie’s story. The Dark Lich is The Masrked Mage Belgar, Heath’s father. Upon seeking to use Dark Magic to heal a girl Belgar became corrupted by Dark Magic and turned evil. During the battle with The Dark Lich the background will change and let you know what type of attacks he will use. His starting background means he will use evil spells like Hell Cross and Deathspell. A watery background means he will use Water and Tree magics. A firey background means he will use spells like Hyper Cannon and Prisoner. Prisoner will turn your entire team into Moogles. His main special attack is called Death Ecstacy.
The Deathbringer is the follower of Jajara and is found in The Bone Fortress. He used to be a terrible ruler of the land, and now he commands an undead army. He attacks with his claws and by using Shade magic. Occasionally he will shoot off gold energy blasts at your or cause bones to jut out of the floor at you. If you have a copy of SAGA Frontier 2 on your memory card you can return to this area for a special fight against him for a sword. You will be confronted by two Skeletons who are actually the Chobin Hoods you fought before the Mantis Ant. After a brief talk with them The DeathBringer 2 will come to fight you. He has absorbed parts of Jajara in this form. All of his attacks have been slightly upgraded and now he can split into two and cause a giant explosion. Occasionally he will have the floor swallow a character and have them drop back in from the ceiling. Upon beating him you recieve a special Altena Alloy Sword called Heishishorin.
The Lich from FFA makes a return in SwoM but with a different purpose. It lives in the Sealed Cave and keeps Dime Tower sealed. It attacks with a spinning scythe which will fly around the room, and it will also shoot fireballs at you.