Why you want to test Sienna: Because it is the best hack out there atm, and I really enjoyed playing the first two betas over and over.
How you intend to do so (how extensive etc.): Well, I have virtually no life outside the interwebz, and I'm really good at finding bugs, and if I don't find any, I search again, then once more, and then....well, there's always viridian forest.
Previous experiences: Beta tested for Pokemon Chrome, and will also be beta testing for Pokemon Grey
Anything else you want to say to try and convince me: Roses are red, Violets are Blue, I made this poem, so I could convince you xD