Looks like it, haven't got there yet but several people have mentioned that it's the last level.
Just buy four killer blockchain cards and the game is actually too easy. I made it to Sia without much effort.
Needs Load Runner type build your own level features and about 100 more levels and challenges.
Also what boss has his arms raised up to each side, I want that card?
which cards do you advise to buy?
crystal dragon, sapphire dragonling
Go to sogassets.com and sort by health, you need to survive hits more than anything else (in my opinion). You can always upgrade your cards to get more attack et cetera. And get four with different elements. Having different spells to use seems to have been very useful.