Eternals is a mistake... You're going to get roasted so hard for this by a lot of influencers.
You're monetizing the ability to get achievements. I've always respected the way this game is monetized. I've spent close to $1000 USD on this game. Monetizing achievements, even partially, is a big mistake. And for what? The market for it has got to be super small.
When I pay money, I like to get an item. You're asking that people pay money, for the ability to earn an item.
There's just something very shady about that and I know it's not going to go over well. It already hasn't. That's why you all walked it back the first time. I get that you all have already projected it to make money and probably even put in project effort to begin it before you announced, but this just seems like it should either be an entirely free feature or nothing at all.
It also seems like it could be something not very transparent in how it's earned. Some of the rankings and skill ratings seem super wonky. Imagine selling something and the ability to earn it is buggy or inconsistent.
Eternals is gonna lose you all some players. I guarantee it. It won't gain you new players. You may net money from whales, but it's going to hurt the game long term. Guaranteed.
Just don't.