Below is a link to a video by a Youtuber Tiny Grimes. The video covers Sith Holocron and how fast it can ramp up the number of dice that are in play. I need to do some theory crafting and see other cards. However at this point, there doesn't seem to be anything faster than this. The major problem stems from it's ability to swap in cards for free, be recycled and ignore the deployment restrictions.
Feel free to share some comments you may have about this.
It currently does not have a clear answer, some will contest that it can be stopped by dice removal, but its not a reliable way. Discard is another option that is also not a clear answer and not reliable either. Most of the holocron decks ive seen currently run the battlefield Salvage Yard allowing them the cherry pick the cards you forced them to discard that synergize with Holocron. Personally I think discard, dice removal and running a battlefield that contradicts their game plan would be your best bet to beat it.
I have been playing(playtesting) a Han/Rey deck that has a decent chance but is still not good enough to stop the holocron. It's a tough tough card. too early to say its too powerful though.
So we have been play testing with Tiny Grimes (The Knights of Ren) and we have a few answers to Holocron with the current card pool. The easiest way to hurt Holocron is to get rid of it in the opponent's hand OR remove potential targets for it. The easiest way is the discard die face. The 2 best cards we have seen be efficient so far are "The Best Defense" and "Close Quarter Assault". We actually discuss these and some more tech against Holocron in episodes 102 and 103 on our podcast. Hope this helps. http://shoutengine.com/KnightsofRen/