There are some side cards i looked up. well i was looking trough the continouos traps and counter traps then i found some cards that can be pretty good.
give your opinoin about them if you like. this is just to help you guys getting a better side deck.
First of all is Stygian Dirge, This cards simply does not allow you opponent to xyz summon if they use one rank xyz deck like rank 4. rank 2 rank 7 etc. so it is realy a good card. and it helps against synchros too. but more against xyz decks.
Found it thanks to Megumi Mamakari
next is Hero's Rule 2, this card i just amazing. since we have soul charge and allot other cards that target monster in the graveyard. this card is an amazing side card if you ask me. it does the job and it is a counter trap so not very cards can stop it.