New Rek'sai's ult is... Underwhelming (garbage)
It is basically utterly useless. Everybody knows you can dodge its damage, and then you slingshot like a warwick who missed her ult into their team. It wouldn't be so bad if it didn't still give a global screech and also require you deal damage to them first. (Basically any low hp champ should expect it after being damaged by her).
Not to mention how they removed the attack speed passive on her ult, so she attacks slower at all times.
Just make it undodgeable, or VERY difficult to dodge, because the requirements to use it are already ridiculous.