|Surgery base||Schistocerca gregaria|
|Manga Debut||1st Mission|
|Anime Debut||OVA 1|
Thien has a modest, well-built body, a rugged-looking face with several scars (most likely obtained during his childhood) and short, white hair.
Thien has a severe character, but despite this, he is a compassionate, kind-hearted person, as seen when he is searching for his childhood friend or when he sacrifices himself to save Komachi and Ichiro.
Thien's first appearance is on board the BUGS-2 spaceship, where Maria Viren asked him about the cockroaches in Thailand. He calmly replies that he has eaten alive one much to the surprise of the crew. That was when he was in the city and was hungry, but couldn't steal food, because he lost a turf war with other street kids and felt he will die if he doesn't get something in his stomach, and then a cockroach showed up.
When they landed on Mars, he thought the environment was not supposed to be thoroughly prepared and wondered if that's because of the surgery they underwent. While walking with Maria Thien questioned the oddity about why there were no carcasses of the cockroaches anywhere in sight. When they were about to pass a significant boulder formation, Thien quickly notices three humanoid aliens and quickly hides behind the boulder, covering Maria's mouth to prevent her from screaming. Thien unable to comprehend what he was seeing, he suddenly decides to contact the captain about their discovery and determine that they should withdraw back to base after they passed. Observing them, however, Thien quickly notices the cerci and antenna on their bodies and comes to the conclusion they were cockroaches much to his shock. On their way back, they saw Shokichi who was about to inject himself and stopped him from doing so since the cockroach was backing away, with Thien stating it was afraid of them. Maria then informs Shokichi that the U-NASA issued a withdrawal order and they should head back to the ship with Nanao, somewhat calming him down. Later after offering God Lee a hand in dealing with them and being refused, he witnesses the invading terraformar that killed Lee easily slicing Maria in half despite her transformation. Watching captain Davis transform to deal with it, Thien started thinking of the reason why BUGS-1 was defeated; A, being that they enormous amounts of cockroaches overran them, B, is that each one of the cockroaches had high combat abilities, or C, being both of the above. He then quickly questions if that the cockroaches were not afraid of them, but rather despised them and viewed the crew to be an infestation that deserved to extermination like insects.
After hearing Yang warning them that there 100 more of them gathering outside and watching captain Davis defeating the invading terraformar, he concludes that they may have had a chance against one, but not against a hundred. After listening to captain Davis and Shokichi's plan and hearing Shokichi volunteering himself as the 2nd sacrifice, he interrupts Shokichi telling him that was just because he wanted to die taking revenge. He angrily asks why he should follow her, telling him that she would not be happy seeing him on the other side. When Shokichi questions him, Thien tells him that despite the differences in nationality and religion they all shared the same extraordinary feeling. He then tells Shokichi that he must survive so he could make Nanao a grave. Shokichi quickly demands who then was going to be the 2nd volunteer and before Thien could volunteer himself, Ichiro stepped in and suggested himself. With the plan now in motion, using Tejas's ability they were able to escape from the ship via the Landrover.
After they discovered BUGS-1 ship, Thien suggests to check it since it may still work. While inside they found that the vessel has transmitted some message, but before they could investigate further they were alarmed by gunshots. Outside, they saw John and Redon killed by the terraformars who were hiding underneath the ship with rifles. When they become attacked by the group, Thien immediately injected himself and started his transformation. Having his surgery based on the Desert Locust, he gains extreme leg strength and immediately decapitates two of the roaches. After all of the cockroaches who attacked them were dealt with, Thien stopped Shokichi who was about to continue stinging a dead bug. When the mist of Mars started to clear, they saw three big pyramids much to their surprise. Dazed at the presence of 3 large structures on Mars, they were suddenly contacted by U-NASA's Alexander via the radio in the vehicle. Questioning Alexander why U-NASA has suddenly contacted them and if it had to do with the roaches, Alexander explained to Thien that they did not want to repeat the same tragedy that has happened before (BUGS-1). Alexander then instructs them that after the insects die, they sometimes hide an egg they produce containing their DNA information. He tells them to find the eggs and destroy them all. At the same time, the three surviving members become alerted to the sound of BUGS-2 taking off.
When BUGS-2 crashes down, the surviving trio goes to investigate inside and quickly dispatches the terraformers inside. However both Ming-Ming and Thien rapidly then runs into the hatched terraformar. He tries attacking it with a fast high kick, but the roach avoids merely the kick and low kicks Thien. The bug kills Ming-Ming with her arm and immediately dropkicks Thien into a wall as he wonders why it was so much more agile than the rest of the roaches. He then noted the cockroach movements were more human-like compared to regular Earth roaches. Seeing Ichiro regaining consciousness and hearing him scream for money, he follows Ichiro's suit in injecting himself more, his skin color turning dark and growing wings. He then quickly disposes of the roaches despite the heavy burden of continuous injections. Noticing the evolved cockroach was strangling Ichiro, he manages to severe one of its arms with the help of Ming-Ming's mantis arm but gets kicked away into a wall with his stomach pierced. However, Ichiro leads to recover and finishes off the evolved roach with Victoria's pistol. Afterwards, Shokichi returns back to them with Nanao's corpse in his arms. Ichiro explains to Shokichi that they could escape using a small pod inside the ship that travels back to earth and two of them should barely fit. When Shokichi questions the two of them, he quickly looks around to find Ming-Ming's corpse and Thien's slumped body. Ichiro then tells him that they had to overdose on the drug to defeat the roaches sadden that the vice-captain instantly died. However while Ichiro manages to survive the overdose, Thien had yet to change back to his human form and it was most likely too late for him. This was due to two conditions; one being that the immune system starts causing a shock and leads to death when the drugs effect continues too long, and second being that the stomach and liver that was supposed to be decomposing the drug was destroyed. When Shokichi ask him why he would go to such lengths, remembering his childhood friend he explains that a cold insect body like him had nothing going to Mars or nothing to do after coming back to Earth and that he fell in love with them who held such a powerful will to live. Thien then questions them if it was disgusting that a mixed up human/bug has said such a thing. Crying in sadness, Shokichi hugs Thien and tells him his tears were hot, that he was human and moreover he was a dear friend. As Thien dies, Shokichi thanks him for fighting beside them, still hugging his friend he had made.
Powers and AbilitiesEditThrough the Bug Procedure, Thien gained the DNA of desert locust. An insect with incredibly developed hind legs, which, if brought up to human scale, could jump easily over a nine-story building. He has acquired extreme jumping ability and leg strength that can decapitate multiple Terraformars with one kick.
While using more injections, his becomes closer to an actual locust, he grows wings and gets even faster and stronger.
- He likes soy milk.
- There is no particular thing that he dislikes.
- God Lee described Thien as "Muay Thai boxer."
- His name means fire and light. (in Thai; Thien mean 'candle.')
- When BUGS2 crews did arm wrestling, he ranked 7th place.
- Hongo Joichi and several terraformars also have the desert locust type surgery.