Special symbols are very effective in fact they can be used along with the Reiki symbols / Karuna Reiki symbols. 

Special symbols do not need any attunement as such but still we do the attunement for them to work effectively though I am repeating they don’t need any attunement as such i.e., they would work without being attuned also. That is there is actually no need for attunement done for that whatever we do is to see that the symbols work effectively for you.

Generally these special symbols are effective against many type of negative energies, negative blocks and negative entities also.
When we use them for 3 to 4 weeks you can see clear results