No idea what block there is, sry
What i know is there is no block for Asmodeon exp/battle. I had Asmo 16 lvl more then me, last time i played him solo.
As for your plan with strong pet dragon, for easy early-middle game. But knight are severely limited comparing with mage. Intellect bonus for spell dmg is limitless, and late game mage with 80-90 int can destroy anything with little problem.
Knight on other hand can get pet dragon on max lvl, faster then other classes. But when you hit pet dragon 60 lvl, that`s it no more. Other classes will get same pet dragon only later.
So dont count to much on pet, to solve your battles. Knight is best with large army/high crit%. Pet dragon become just a companion after 30 hero lvl.