
Use Coin for ordinary progression you need now, including merchants and gear-slot enhancement, while keeping a working buffer. Upgrading a weapon slot is safer than it looks because the enhancement belongs to the slot, not the individual weapon. Spend naturally recovered Energy before it overflows, but save refill items for a named activity. Treat Echo Jade as a deliberate premium spend, and never buy a weekly item only because its timer is red.
Safer upgrade
Gear slot; progress survives weapon swaps
Hard-spend currency
Echo Jade; premium purchases and Arena reset
Regenerating resource
Energy; spend before overflow
Current Global currency names include Coin, Jade Fish, Commerce Coin, Echo Jade, Echo Shade, and Taiyi Stone. Older Chinese guides may use Baoqian or other regional labels; do not silently map those names to Echo Jade without checking the icon and shop description in your client.