Acererak

Acererak is one of the most powerful liches and necromancers in the multiverse and is feared by many. He seeks to achieve a higher form of undead existence and ascend to godhood. In some adventures, he attempts to become a deity of death and destruction.
He has a vast collection of artifacts and treasures placed behind a pile of traps, puzzles, and monsters in his tombs to lure unwary intruders and potential thieves into a trap. His most notorious dungeon, the Tomb of Annihilation, contains a machine that devours souls and further empowers him.
He plays the role of the main antagonist in the campaign book “Tomb of Annihilation.” Players who confront him must prepare for deadly dungeons and unfair traps that only the smartest adventurers can survive.
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Iymrith

As the role-playing game is called Dungeons & Dragons, dragons certainly cannot be missing among the most powerful adversaries. In particular, the chromatic dragons continue to pose threatening challenges to adventurers.
One of the more powerful among them is Iymrith, a blue dragon also known as the “Dragon of Statues.” She seeks to exist as a goddess, and any means are right for her. Not only is she powerful in combat, but she is also a cunning intriguer. She primarily manipulates Serissa, the daughter of the storm giant king Hekaton, to achieve her own goals.
Iymrith lives in a desert city ruin and collects magical artifacts to further increase her power. She also has a penchant for traps, illusions, and ancient magic, which she eagerly throws at her opponents. She is the main adversary in the campaign book “Storm King’s Thunder.”
Xanathar

Xanathar is the most famous (and entertaining) Beholder. He is highly intelligent and possesses 10 magical eyes, each housing different abilities. The Beholder is extremely paranoid and hot-tempered, often labeling his own followers as spies – which usually costs them their lives.
He is the boss of a criminal underground empire in the city of Waterdeep and is one of the most dangerous crime lords in the world of Dungeons & Dragons. His Achilles’ heel is his beloved goldfish Sylgar, which often provides his adversaries a bargaining chip – or leads to their immediate death.
Xanathar is one of the villains in the campaign book “Waterdeep: Dragon Heist” and is a focal point in the rulebook “Xanathar’s Guide to Everything.”
Page 4 continues with Vecna and Tiamat.