Nice to see your collection growing and that you slowly get your foot into diamond. Summoners are very important and I have finally also started to level them up. I was more focussed on monsters first and renting the summoners, because of the dec costs compared to the price was better than renting monsters (APR).
With the Chaos Legion Sale ending soon I am trying to get some bargains, before the price are getting higher :)
!PGM