Or maybe just nerf the rediculous damage on his Q a bit? Bufing the ap ratio from 0.6 to 0.8 was huge, maybe tone it down to 0.7...
Or nerf the health but bring back the old one on top of the new to force him more into a mana focused built.(ok, apprently that's what they wanted to avoid with the rework)
And nerfing the W certainly is needed.
Also, his passive seems quite absrd, atleast especially in lane, nerfing that passive especially early on should help alot.
But just nerfing his tankiness is the totally wrong way to go about it.
Finally, we’re shifting Poison Trail’s damage from base values into scaling so Singed can feel good about building damage
Well, that's where riot fails in their thinking. In order to feel good about getting damage, you either need save ways to apply it(range, mobillity+quick burst), or you need enough base survivabillity to get away with it.
It doesn't matter if an AP singed deals tons of damage if he just gets vaporized befor getting close to anyone.
For the saim reason, the Reksai rework fails. Her dominant built in high elo is once again tank, and even after the base nerf/ratio buff on pbe, she will either stay tank or fall of meta. On a kit like hers, you can't afford to be squishy, it does not work, so it doesn't matter how high her scaleings are, if she goes for off items, she will fall off pretty fast as she has no way to utilize that damage in teamifghts.
If you want champs to get off-items, you need to make them rely less on def-items for their survivabillity(note that survivabillity is not equal tankiness), that's the only way.