I was in the closed beta. I saw what was actually in the cash shop, and it was horrible. The whales will be spending hundreds of USD to get level 10 wings and lock down every MVP. Max level wings take an insane number of diamonds, and give +1000 ATK/MATK and +20% atk/atk on top of that. A level 99 trans character doesn't even approach that enormous number. This one, several hundred dollar item, gives unbelievable power.
I can understand f2p titles including tangible advantages like faster leveling or shortcuts to making a guild or effective character, but there's no amount of careful planning, extra grinding or clever play will ever let a moderate spender compete with a whale. The power gap has to be seen to be believed. You will never "earn" your way to what the whales have because the whales will never let you participate in any of the game's lucrative income sources. There's no MVP lottery. You're not going to be on any of the rankings and you're not going to get the last hit.
You've been warned. Players of real games, don't fall for these abusive pay to win mechanics. Show companies that exploit players that this isn't a sustainable practice by walking way.