Height: 52m
Width: 58m
Length: 103m
Weight: 3800 tons
Speed: 600km/h
Power Output: 3500
SaiDain was a rhinoceros carved out of stone by Master ShaFu and left within the Beast Origin Village. It holds the Fierce Ki Soul of Bruce E. In Episode 32, Mele and Rio use the SouJyuto to encounter it. In Episode 35, when Ken finds the Scared Ground under fire, he concentrated on what Bruce E told him, to listen to his body. It unlocks his powers and the SouJyuTo left Rio's hands and went to Ken. SouJyuto then brought the GekiBeast to life. When Ken activates it, Beast Power Blooming was born. It showered the young JyuKen users (Jan, Rio, Retsu, Gou, Mele, Ran, and Ken) and powered them, unlocking the key to hidden abilities. 'Sai' means Rhino in Japanese.

Height: 70m
Width: 40m
Weight: 3800 tons
Speed: 650km/h
Power Output: 3500
GekiBeast: SaiDain
Formed differently from the other GekiBeasts, SaiDaiOh's head can be concealed in a faceplate to evoke its Defense Mode and it uses the SaiDaiken (Break Big Sword) from rom the horn and a shield formed from the rhino's back. Ken/GekiChopper maneuvers SaiDaiOh. The first to be defeated by SaiDaiOh was Kata. The other Gekiranger can also pilot along with him. Miki once piloted it and defeated a GenJyuKen user in Episode 39. In Episode 43, Ken unleashed the new Big Ice Floe Mountain that unleashed an ice to freeze Shuen. He also used this technique to create a ice statue depicting a young boy's deceased mother as a Christmas present.

GekiBeasts: GekiGorilla, GekiPenguin, GekiGazelle, SaiDain, and GekiWolf
GekiGorilla to form the centaur-like SaiDaiGekiFire, with GekiWolf, GekiGazelle and GekiPenguin riding on it. SaiDaiGekiFire combines the energies of Extreme Ki, Violet Fierce Ki, and Fierce Ki Hard Diamond into its attacks. Its main attack is Fire Break Big Assault, in which the GekiBeasts ram themselves at the opponents before the SaiDain lifts the opponent up with its horn for GekiGorilla to slam the opponent with its extreme punches. It was first introduced in Episode 35 and its first opponent was Maku.

GekiBeasts: GekiTiger, GekiCheetah, GekiJaguar, SaiDain, and GekiWolf
GekiTiger can combine with SaiDain to form SaiDaiGekiTohja, with GekiCheetah, GekiJaguar and GekiWolf next to him. Break Big Firm-Firm Attack creates a whirlwind to send the enemy skywards. Then GekiJaguar, GekiCheetah and GekiWolf attack the enemy, and SaiDain finishes it with his horn. It was first used in Episode 42.

GekiBeasts: GekiTiger, GekiCheetah, GekiJaguar, RinLion, RinChameleon, SaiDain, and GekiWolf
It is first introduced in Episode 47. Once Rio discovered Ron has been manipulating him since he was a child and after Jan's urging, Rio and Mele joined forces with the Gekiranger and defeated Ron together. In its attack Break Big Geki-Rin Slash, SaiDain lifts up its opponent towards the sky with its horn. GekiCheetah, GekiJaguar, and GekiWolf attack the enemy, and on the way down, GekiRinTohja executes its spin-slash attack with the GekiRin Sword.