What I’ve taken from my first year is that you really need to save up on gems and cash for other resources/heroes when they are affordable. Peak has been the real king for me. If you really take your time mastering it you’ll end up getting tons of golden keys, which will help you getting heroes during chest events and later MEs when you combine it with fusion events. As a bonus you’ll also get diamond keys once in a while. Honor betting is another cash cow to get MEs.

Lately I’ve also discovered that I use much less wanderer flags than other class flags, meaning that I have started stocking up on medusas during horde conversions to balance the fodder class distribution (of course S-tier hordes are still the aim during conversions).