The Olympiad time changes, 5 matches per day, and weekly Heroes will NOT be included in our update. It has been delayed to a future update.
In case you are wondering why buff/potion use was implemented, please see the Dev's reasoning below:
"Olympiad is content where individual players compete, so the outcome depends highly on certain items that are allowed or certain classes that are advantageous in the game. We have been constantly balancing Olympiad for a long time while running the match in limited ways, but this cannot resolve the imbalance and it is now naturally settled in the game. To change this, we made changes to Olympiad by opening all environmental elements so that players can now be stronger as much as they prepare or invest in their characters. Therefore, the winning rate can be increased according to how players set their characters and the variety of buffs they prepare, regardless of class type."