The most important advice I can give about medals: The new weekly event will have some medals attached to the shop and reward tiers. But while said medals are GREAT they will only last for that weekly event. They will be exchanged by Medal/Badges of Seasons after the event ends.
Don’t get me wrong, The Medals/Badges of Seasons will improve your teams, but EVERY other weekly event like that will keep awarding them so you don’t need to spend a lot of your gems to get a full set right away.
My opinion about the event based on the first one we had: It sucks, you will have a sequence of battles awarding RANDOM little prizes that can affect your score. Stronger enemies have better chances to drop said items in larger amounts, but that’s it. CHANCE.
You can face a level 100 team and earn 5 Skulls (the item on the first event) and a guildmate can face the same level 100 team and earn just 3 Skulls…
Things can maybe change in teh upcoming event given all the negative feedback from the players, so take this opinion as it is, something based on what happened in a given timeframe.