I find that shard shop is a great idea, but not well implemented.
So, its upgrade, Legacy Mode.
Unlocked when you get the first 7* toon.
Then a tutorial comes in, which shows you a one time node, which gives you 330 shards for your first 7* toon only. Using this and a Legacy Token allows your toon to get a Legacy tag and to be used in this Legacy Mode. Their will be nodes, proving Legacy Tokens (first win only) and Legacy Shards (0-5 Legacy Shards), which are basically shards for Legacy Toons, which are used to purchase things in the Legacy Shop (Shard Shop). Conversion: 10 Legacy Shards=1 Shard (basic shipments), 50LS=1 Fully Crafted premium gear and 50LS=1 Exclusive Shard.
Each node requires 10 Legacy Energy and at least 1 Leacy toon.

Differences in normal and Legacy Toons.
Normal Toon stops to develop at G12,7*,Level90 (Max we have seen for any toon, PvE included).
Legacy toons have same stats as maxed out toon at start, but have their level and gear reset, allowing you to boost them further.