I know a lot of people look at Syndra as this 'no skill press R to win' champ, but there's no denying she's struggling at the moment. On a lot of the stat sites her winrate is around 45-46% with a 2% pickrate, which are pretty miserable stats.
I feel like the best thing for Syndra is to give her more skill expression when using her ult, so she can be buffed without feeling unfair to play against. I think that adding a passive that makes her ult do more damage the more abilities you hit someone with would be a good start, and would allow for buffs on her other abilities.
I just love Syndra's playstyle and thematic so much it hurts seeing her in such an awful position, we need to bring her power back!