The Triton Jackson Chronicles: God of Madness

When you're the son of Percy Jackson and Annabeth Chase, nothing is considered unexpected for young Triton. That is, until the unexpected happens.
There is a new threat.
The Titans have spawned with mortals and had demi-Titan children.
When the evil half bloods kill Triton's best friend, Kyle, and kidnap Dionysus, it's up to him to restore justice.
And avenge his friend's death.