Vecna is portrayed as one of the top-tier “endgame” antagonists in both Dungeons & Dragons lore and in Stranger Things, but his strength depends a lot on which version you mean.

D&D Vecna

• In Dungeons & Dragons, Vecna is originally a mortal wizard who becomes an archlich and eventually a godlike figure, putting him among the most powerful entities in the setting.

• As a lich or demigod, he typically commands high‑level magic, can paralyze or kill with a touch, survives even when reduced to just a hand and eye, and often functions as a final‑boss enemy for epic‑level parties.

Stranger Things Vecna

• In Stranger Things, Vecna (Henry Creel / One) is presented as more powerful than Eleven in a direct one‑on‑one clash, mainly because he has had his powers longer and understands them better.

• He amplifies his power by absorbing the life and minds of his victims, combining his own abilities with those of other test subjects and monsters he dominates in the Upside Down, which makes him the main existential threat of the series by Season 4.

Vecna in Dead by Daylight / games

• In Dead by Daylight discussions, Vecna is often described as one of the strongest “killers” in the in‑game lore, thanks to his magical abilities and intellect, sometimes even called the strongest killer currently in the Realms.

• Even in pure D&D game terms, analyses tend to place his stat block as an “epic” level opponent: very high defenses, powerful spellcasting, and multiple special resistances and reactions, suitable as a capstone villain for very high‑level characters.