Intense Serious in Chinese / Japanese...

極度 means extreme, intense, and sometimes maximum or zenith depending on context.

The first character means extremely or utmost.

The second character means degree or capacity.

真剣 is a Japanese word that means intense, serious, or earnest. It describes a person who is deep, serious, and a true thinker or dreamer.

Literally, this means “true sword,” as compared to a sharpened wooden practice sword blank. It's real, true, and serious.

深刻 is a Chinese word that is the form of intense that describes a person who is deep, serious, and a true thinker.

If you find yourself contemplating the world and coming up with profound ideas, this might be the word for you. In some contexts (especially Korean), it can mean seriousness, gravity, or acuteness.

In Japanese, this can mean “serious problem” or can be a rare given name, Misa. You should not use this if your audience is Japanese.

激烈 means fierce in Chinese and has a similar meaning in Japanese Kanji.

This can also be translated as intense, violent, vehement, furious, or fervent. 激烈 is more the violent version of fierce in Korean.

烈 is a Chinese word that means ardent; intense; fierce; stern; upright; to give one's life for a noble cause.

In another context, this character can refer to one's exploits or achievements.

In the Buddhist context, this is burning, fierce, virtuous, and/or heroic.

While technically, it had the same meaning in Japanese, it's usually a female given name, Retsu in Japanese these days.

In ancient China, 饕餮 was a ferocious mythological animal and the fifth son of the dragon king.

饕餮 can also refer to a zoomorphic mask motif found on Shang and Zhou ritual bronzes.

As an adjective, this can mean gluttonous, sumptuous (banquet), covetousness, greed, avarice, or intense desire.

三昧 is the Chinese, Japanese Kanji, and old Korean Hanja way to write Samādhi.

Samadhi is the state of intense concentration achieved through meditation.

Some will define Samādhi as putting together, composing the mind, intent contemplation, perfect absorption, or union of the meditator with the object of meditation.

貞烈 is the Japanese Kanji for “Extreme Faithfulness.”

The first Kanji means “firm adherence to one's principles,” chastity (of a woman), chaste, etc.

The second Kanji means ardent, intense, fierce, stern, upright, to give one's life for a noble cause, exploits, achievements, virtuous, and in some contexts, heroic.

Now you get the idea why this refers to someone who is extremely faithful (to a cause, themselves, their religious beliefs, or their philosophy.

棋 is the most simple or generic way to write “chess” in Asia.

棋 is part of other more specific words for board games of strategy such as the western version of chess, Chinese chess, Weiqi, or Go.

In Japanese, this single character is pronounced “Go” and often refers to the game known in the west as “Go” (not just the 5-in-a-row version but also the complicated encirclement game of strategy known in China as Weiqi).

In Chinese, this can be more ambiguous as to which game of chess you speak.

If you like any version of chess, or games of intense strategy, this can be the character to hang on the wall in your game room.