Answer:
I'm a god. I'm a planet. I measure heat.
Don't do this in the shallow end.
I have legs but never walk, I may have flowers but no soil, I hold food but never eat.
Two in a whole and four in a pair. And six in a trio you see. And eight's a quartet but what you must get. Is the name that fits just one of me?
My first is in wield, sever bones and marrow. My second is in blade, forged in cold steel. My third is in arbalest, and also in arrows. My fourth is in power, plunged through a shield. My fifth is in honor, and also in vows My last will put an end to it all.
What is 9 added to any number ending in 1