I really like the Mephisto RDA I purchased to match with my Akuma mod. The copper sleeve really matched well well with the copper mod. The huge holes on the Mephisto looked like it would be an easy build. After building coils with 28 gauge wire I was very happy with the performance. That is until I notices after a little bit of use my coils were firing unevenly. the solution was to build a sleeper coil. The sleeper coil uses only one piece of wire. After wrapping the first coil installing it on one side of the RDA then taking the long positive end of the wire and wrapping it on the other the coils fired evenly. It took a little practice to get the second coil to my liking I now use this coil build on this Atty all the time. Bothe sides fire evenly. Tried the same build on my TOBH and it doesn't work as well plus the wall on the TOBH makes it harder to build. if you are having trouble getting coils to fire evenly try the sleeper coil.