Correct!
My subordinates may sing their own praises
By shouting their strengths,
The other 4 members of the pagoda would yell out what they represent, or their strength, whether it was power, magic, speed, or weapons...
But this changes here!
Everything is my strength!
...But for Godo, everything is his strength! Omni literally means everything, or all.
Go on, say it with me! Sing my strength!
This line was to tell the reader what they were looking for. It commands the reader to say Godo's strength, so you come up with "Omni Change", because, as said above, everything is his strength.
As a whole, the riddle is very arrogant, which fits Godo's personality well, from what I can remember.
Good job Karifean!