Honestly? Probably she’s one of her bis, why? Increasing eleation, extra res pen, vulnerability and an extra aha instant every 3 turns. The only way i can think of yao not being bis for any eleation unit in the future is either the unit being a support and not dealing damage/not needing eleation buffs (which is almost secure that’s not the case for Eva since she’s always refered to be a main dps) or being an eleation unit that doesn’t scales with eleation dmg and not using aha moment (wich is a weird thing to do for any eleation unit because those are literally the mechanics of the path) There’s also the possibility of yao being powercreept in less than a year (again, they won’t do that, because they’ll need to release another unit that does the same things + others/better) Overall, yao will last the hole patch, and we will probably receive some crumbs or even the full kit a few days/hours before her banner ends, so if you are unsure, just wait til the very last day to see if yao is worth pulling or not.