Anakin began to succumb more and more to the temptations of the dark side

Palpatine promised him the power and the ability to save his beloved from death. In return, Anakin had to betray his friends and surrender himself completely to the Sith.

The first step on the path to transformation was the killing of the younglings — Anakin felt remorse for his actions, but the dark side of the force grew.

Until he finally sensed your presence. And Kenobi's on Mustafar. He went to see them.