I didn't deal with this game much last week, but the next 15th season started this week. Because of this, I spent more time for the game.
I'm still not sure that the Season Rewards can be achieved at no cost. However, crafted items can be sold.
Hopefully, thanks to this option, I will be able to obtain some income over time. It can only be from sales, but spending well from there, probably from Arena Battle, as well. They made some changes, updates in this week.
Updates
In Season15, I tried to choose weaker opponents, which only succeeded in the first 5-6 battles, as my points have grown so much that we can no longer choose the weaker opponents. So after 1 day (max 8 Battle tickets a day) I also made the maximum out of Season. Of course, if I continue to develop and put new, higher levels of items on the hero, then this may be better.
Each victory means 1 Arena Medal and a rare other item. I managed to win 6 Fights out of 8, now I stand:
I still have no idea what the green 18 under my points. However, I am the best from 18s.
There is a Mission Counter on the main side of Season. Which is on 6/160. Unfortunately, I couldn't find what I could win with the 160 victories, not as if I had the opportunity, because if I win all the fights in the next 9 days, it's only +72.
That's what it would be today. Slowly but surely I know the game and, based on my own experience, realize how the best to do it. Hopefully I will have more accurate information about the sections currently in question next week.