It’s Magna Defender, from Power Rangers Lost Galaxy.
He rescues Leo, the Red Ranger from an explosion.
The Rangers arent sure what to make of him, he’s reclusive and secretive. The villains, henchmen of Scorpius, are searching for a source of power, The Lights of Orion. Magna Defender wants the power as well, and even clashes with the Rangers in an attempt to get them.
Later we learn his motivation. He was a warrior, along with his young son, Zika.
They were attacked by Scorpius, who captures Magna Defender. Zika attempts to save him but is murdered by Scorpius. Magna Defender plans revenge for his son. He is defeated by the evil warrior Treacheron. He falls down a deep chasm, powerless, and trapped in time. Eons later, a man falls down the same chasm, and Magna Defender possesses him to regain his power.
This man was Mike, the brother of Leo, the Red Ranger.
Magna Defender is wounded in battle.
His son appears to him and tells him to give up on revenge, and be the hero he once was.
He sacrifices himself to save the space colony, Terra Venture.
Mike is freed from Magna Defender and rejoins his brother.
Magna Defender and Zika appear to Mike and give him a morpher, he has been chosen to become the new Magna Defender.
His morpher is destroyed, and he loses the power of Magna Defender eventually.
He apparently regained it offscreen by Super Megaforce, and now jokes with Phantom Ranger about helmets or something.