it would be great if the thingies which you use to evolve the startup event buildings were not event-specific and could be used to evolve buildings from any event. Would also be good if you could craft them in the MA.
Most likely you wont get a universal artefact because inno want you to try hard on the specific event and when you only get 7, you will spend money to get the last 2 or so they hope.
If you had a universal artefact then people could then save the artefacts when they don't want to place one of the evolving buildings and then upgrade the next one without effort. Also with this never ending type event some people managed to get 30-50 artefacts they could then not participate in next few event and still upgrade.
with regards to a universal evolve instant. It would be great if you could get them to allow you to fully evolve event buildings . 1 could be put into a chest used within the weekly tournaments similar to the blue print instant that`s in chest 10. maybe put it in at chest 8 on t3 goods tournaments as opposed to a fixed weekly reward. This would help reduce the amount that players can win or cap the amount you can hold. Possibly even have them time limited ( something that inno do in the FOE game, with forge points that are gained from assists)
Not everybody can win the full evolves required with in the game time frame as real life events kick in or buy diamonds. At least this way they may have that chance.
It would be nice to maybe have crafting recipes to CHANGE artifacts to other types though. Such as turning extra mermaid artifacts into phoenix for a cost of spell fragments. And if they take up crafting recipe slots people would be more likely to build sub-10 evolving buildings too instead of just hoarding everything until they can get them to max level...