3-color arc structure?

WUB — Enters/leaves graveyard triggers

UBR — Shuffle triggers (Enshrine)

BRG — Discard matters

RGW — Mourning

GWU — Landfall, land diversity

Alternate structure:

BGW — Mourning, Enters/leaves graveyard

RUG — Scouts, landfall

UBR — Shuffle triggers

WRB — Exile triggers, kakamora

GWU — Land diversity, menehune