Tesshin Sakuma is a muscle-bound fitness nut who pilots the Nursedessei battleship.
Tesshin will be played by Tadashi Mizuno, who previously had a minor role in Ultraman Geed as Riku's boss.
Himari Nanase is the calm and collected operations specialist who uses VR glasses to control the combat mech GUTS Falcon.
Himari is played by Meiku Harukawa, who previously appeared in Ultraman Ginga S is a member of the Victorian race called Hiyori.
Seiya Tatsumi is the captain of GUTS-Select's expert team.
Seiya is played by Katsuya Takagi, who previously appeared in both seasons of Kamen Rider Amazons as Kazuya Misaki (one of the initial exterminator team), and more recently as the human form of Juran in the TELASA special' Kikai Sentai Zenkaiger Spin-Off: ZenkaiRed Great Introduction.'
This new role means that Katsuya joins the elite few who have played roles in all of the big three henshin hero franchises.
Ignis is an alien treasure hunter from the planet Lishuria. He normally looks just like a human, but when excited or emotional "the difference becomes clear" (which I guess means he has an alien form too).
Ignis is played by Kei Hosogai, who previously played (another space pirate!) Basco Ta Jolokia in Gokaiger.
The Nursedessei is a 40m long battleship piloted by Tesshin. It is GUTS elect's primary vehicle when going into battle against monsters.
It appears to be based on a flying saucer called "Nurse" from Ultra Seven, and although it's not yet confirmed that this can transform the "Nurse" was able to transform into a space dragon, so I'd expect something similar to happen here.
The GUTS-Falcon. Drone aircraft superficially similar to the "GUTS Wing" from Ultraman Tiga. But unlike Tiga's planes, this can transform into a "hyper mode" mecha. Remotely piloted by Himari.