Another two mega refils got me 5 4* shards out of 40 runs, so I would say they drop with a 12.5% overall rate for me.
As you went through 3600SoT, which gave give 103 runs on itself, but given SoT return, I would round it somewhere around 120 runs that you've squeezed out of it (that number is EPIC).
So, drop rate for 22 shards from 120 runs is around 17%
I'll revisit these numbers again, when I get some ironite, but we roughly know what to expect now- thanks for reporting!





