Some characters don't need a long speech.
Some don't need to prove anything.
They just appear, and the entire atmosphere changes.
Five of them are:

Muzan Kibutsuji — Demon Slayer

Calm, elegant, and terrifyingly composed. He carries an intimidating presence without needing to raise his voice, making every appearance feel significant.

Sung Jin-Woo — Solo Leveling

Quiet and increasingly intimidating, with a powerful presence that commands attention.

Aizen — Bleach

Elegant, composed, and always mysterious. His calm confidence gives him an unmistakable presence.

Levi Ackerman — Attack on Titan

Calm, disciplined, and incredibly composed. Levi doesn't need to talk much to make his presence felt.

Ryomen Sukuna — Jujutsu Kaisen

Cruel, confident, and intimidating. Sukuna's presence alone creates a sense of danger whenever he appears.