A new type of flag has been added: MOXIE. They provide a maximum of 20% DMG reduction to your heroes at LVL 5.
To get this new type of flag, ask your guild leader to upgrade Magic Bureau to LVL 5 and then upgrade Moxie to LVL 5.
You can buy MOXIE in your Guild Turf -> Magic Bureau for 30 Shards and they last for one hour.
Is your guild low on shards? You can buy them here: Buy shards