Helios. The personification of the Sun. One of the few Titans the Gods didn't even bother trying to wrest power from, and he's also the guardian of oaths and sight. He was so powerful that driving his chariot wrong could destroy the earth by freezing or burning it simply by driving too closely to or too far away from the ground.

A loving father too. In the most prominent myth that features Helios, his son Phaëthon (the umlaut just means to pronounce the E) made a pilgrimage all the way East to confirm that Helios was actually his father. Phaëthon was extremely brave, but also boastful, to the point that somebody finally said something along the lines of, "Oh, whatever! I bet the sun god isn't even your real father." Cause he was a mortal, even if your mother and sisters are nymphs, hearing that your dad was the fucking sun is still a bit of a stretch enough for Phaëthon to have some doubt.

Helios confirmed Phaëthon's parentage, and to dispel any leftover doubt, made an oath to his son that he would grant him a favor as long as it was within his power. Unfortunately, Eos the dawn had just pulled up with Helios' glorious, gold and silver chariot pulled by 4 flaming horses so dude could make his daily run. At that moment, Phaëthon decided on the favor. his son asked to drive his father's chariot. Helios, being the god of oaths, begged his son to reconsider but ultimately had to keep the oath he swore.

Being a mortal who also had no idea how to drive the chariot of the sun, Phaëthon lost control. At some points, he went so high he was almost stung by the constellation Scorpio, and those places became irreversibly frozen into tundras. At some points, the chariot drew so close to the earth that some places turned into deserts. Zeus saw what was happening, and to protect the rest of the world, shot Phaëthon down with a lightning bolt.

Phaëthon's body fell into the river Eridanos, and his sisters who went to find his body mourned so intensely that either as a mercy killing from the gods or because magical biology just kinda works this way in Greek mythology, they turned into poplar trees and their tears became amber.