Solaris is the final boss of sonic 06 and is probably the strongest boss in sonic history due to 3 super hedgehogs beating it and solaris is said to eat infinite timelines. once beaten phase 2 happens and solaris looks like this.

Solaris is the original form of mephlis and iblis but solaris split thanks to duke of soleanna and once mephlis obtained all 7 chaos emeralds they formed back into solaris.