How to get many feather?

Hm are very important alot of people grind them out.

It takes a good 3-5 months worth of feathers to be able to save up that many feathers. You really need to score good on arena to be able to do this.

And ye you can grind out hm to help you get 200k+ feathers faster

From both arena and arena assault I get 10k feathers every week, so it's a 5 star every 2 week.
Sometimes when events are up I can even earn 20k feathers every week.
Obviously being F2P I needed a lot of months to gain enough feathers to have a good enough tier 20 team and enough good 5 star for arena assault, but I Guess is doable in some months with all the stuff they're giving lately.
Also starting the First day It launched helped, but around Summer I even quitted for some months.

Clean all the events you can, daily quests, arena, each time you finish a story mod chapter don't forget to go in the nintendo shop (100 coins = 2000 feathers). And more important now, farm HM with GHB.

You can grind out HM overnight with macros and GHB. I don't do it, but it's the best way to get a shitton of feathers if you're really serious about the game.

Basically, do Arena and Arena Assualt every week and try to get the max score possible. (There are Daily Arena quests that give 100 each time, 700 per week on top of the Arena rewards.) After that, complete all of the Chain Challenges on Normal and Hard for feather rewards. Then, grind Hero Merit during Tempest Trials, Chain Challenges, or the GHBs. These are the best ways to earn feathers quickly.

As I'm currently sitting on 194k feathers, I would advise you to do every quest, including the dailies, also, every event adds up, even if you're not on the top players