How are we supposed to give you advice if we don't know how many points you could get for the fusion summon rush / champion chase if you use up all your voids now? You'd have to run the numbers, figure out what other shards you have, or will get in the near future, perhaps some fusions / fragment champions you have saved up that you could do during the next champion chase, and so on - then see how many void shards you'd probably still need to have left. 

But in any case, if you have 30, you could surely use a bunch of them. Hopefully you'll get lucky. Personally, I have exactly 1 left, so... :P 

Im  pulling  all  of  mine.  I  have  24  currently,  and  hopefully  ill  snag  a  couple  more  from  UNM.  I  have  5  (soon  to  be  6  from  monthly  quests)  sacreds  though  and  will  probably  have  10-20  ancients  by  that  time  too.  It  depends,  like  L9753  said,  how  many  other  shards  you  have  and  expect  to  get.

I'm wondering the same question. I saw the HH video about Brogni, and was like "OK, this fusion, I'm gonna do it"... 

But I wasn't able to gain more than 15 shards for Yoshi, and I'm wondering if there is a point in even trying? 

I'm level 55, FTP, in between early and midgame, with 3 6*, cruising in dungeons 14, I'm not competitive in Tournaments, stuck in Arena Bronze II (like everybody else)... I guess I should open my 6 void shards, shouldn't I ?

My advice would be YES & NO.

Why YES: x2 event is the best event for pulling shards. 

Why NO: double dips would be better. I mean I would save shards till FUSION Event, in case there are x2 event during FUSION event, it's 1 arrow 2 birds.