Ways to get 4* AMs

It’s been almost a year and I’ve reached the point in my career where I have enough of all 3* mats but need a tonne of 4s. Of course there’s one available every 10 days or so in rare quests but what’s the next best way to get your hands on them?

I’ve finished top 1000 in rare a couple of times but for epic you have to be in the top 500 which has always been out of reach for me. I can complete legendary each month but nowhere near the level of competing for top 1000 - I only have four fully levelled 5-star heroes. PoV is one more every 50 days (although I missed out last month - my alliance let too many titans go). If titans are the best way to get them I should probably switch alliances as I’m always the top or at worst third hitter but we’re only able to take down 6 star titans.

Hiya, please use the search function in future… Literally searched “ascension materials” and this is the top result…