Ruling Help About Priority of Damage/Heal

[RealSlim]

Hi, I'd like to ask a question:

If I attach a Rainbow Energy...

...to my Onix...

...and my opponent has an Ampharos...

...what is the correct sequence to inflict/heal damage to my Onix (due to the effect of Rainbow Energy and the effects of Onix's and Ampharos' Poké-Bodies)?
Thank you so much!

 

[Brave Vesperia]

I'm sorry, but we don't answer questions from the Professor's Exam.