What a great idea, complete 5 raid wins to open a treasure box to get fragments of an EHT in diamond and platinum. Treasure boxes respawn every 1.75 hours it seems. (Edit, seems to be every day after the first box)
The treasure box is in addition to the regular Heroes chest!
E and P should do the same
This shard idea is not new though as I know at least @Kerridoc has mentioned it a long time ago in relation to ascension mats (I think, correct me if I’m wrong)