If there are 3 players, then the game should look:
OPTION1.
Player 1 does upkeep, then encounter then mythos.
Player 2 does upkeep, then encounter then mythos.
Player 3 does upkeep, then encounter then mythos.
So there are 3 mythos phases?
OPTION2
All players do upkeep, then all players do encounter, then active player does 1 myhos.
Final battle question:
When I cast spell at the begining of final battle (e.g. +6 to combat), will it last until the end, or until 1 round (all players attak + AncientOne attak)?
"a gate and a monster appears" encounter.