I'm going to send an introduction letter to an editor and just wanted to make sure I don't fail too early :-) Is it correct/understandable to say "I'm an employee of XYZ with some assets as blogger". I'm just trying to avoid some clichè statements like "I have experience as ..."
It is just about understandable but looks really strange. An asset is something you own or have the use of even if it's something intangible like a qualification or skill set, it certainly isn't what you do for a job. The computer or tablet you use in your work would be an asset as a blogger as would your ability to type but the work you do for XYZ is not a collection of assets, it's a set of responsibilities or tasks.
If you want to avoid 'experience' you could say "I am employed by XYZ with some responsibilities as a blogger" or, if blogging is the main aspect of your job, you could say "I am employed by XYZ as a blogger"