I'm still finding the bottleneck to be 3* Rainbow Runes
Played 80 SoT last night Undrworld Madness before bed (Mainly Game of Death) - two 3* Rainbows in one drop
Played 80 SoT this morning in Battlefield Madness (Mainly No Victory) - one 3* Rainbow rune
Very similar to what I saw before the update
3* Rainbow shards? Falling like snowflakes! But not really exciting me because what's the use of evolving characters without the Talismans to support them
Will continue tracking this...