I never know what to put in these. It's an aggressive combo deck designed to swarm the field with graveyard special summons in order to combo off into the boss monsters and create interruptions. If you're going second, the side deck is covered with ways to out the more common boss monsters that have destruction protection, and also a way to turbo into Kali Yuga, one of the best "going second" boss monsters you can land on imo.
Like any other D/D/D deck, consistency issues can appear once in a while, but in play testing against even the grindiest control decks, I've found ways to survive and end on strong boards.