Made a deck with one off my all time favorite cards, Mega steelix.
And it works pretty gosh darn well you will love this deck
Use Magearna to switch between tools for Steelix
Use Bastiodon ability to block all damage from pokemon with special energy (Pokemon research lab to put Shieldon on bench)
Use Dusknoir ability to swich your special energy between Steelix so it does not get discarded
Prism Diancie for 20 extra damage
Crystal cave to heal 30 damage each turn
Special energies to reduce opponents damage along with metal frying pan
Have fun guys