From the look of your tat its quite light anyway and a good artist should be able to cover it well, just need to spend a bit on a big design ive turned my cover into a sleeve now but a dragon should be fine good luck!
I Had a black panther covered up on my arm recently but before the tattoo i had a couple of laser sessions not to remove it just to lighten it a little which helped the artist cover it easier it only cost £40 a session well worth it in the end
