Burst beyond burst
As you can clearly see in the link Syndra misses all her abilites on Ezreal then just clicks R and ignite on Ezreal and then he dies. From full health to dead in literally one ability.
This discussion isnt about flat out nerfing Syndras ult damage, but changing her ult so that it has some counter play. Think about veigar ult for a second, it can only burst a champion if the champion is missing a certain amount of health (typically half their health or more is missing), with veigar you know if you are missing half your health you need to play very safe and further back. With Syndra anytime she has 4 or 5 balls anywhere on the map you are in danger of dying no matter your health (unless you are a tank, but im talking about mid laners so mostly mages and assassins). While the counter play to syndra and veigar ult are similar, standing futher back and playing safe, veigar ult is only a threat if you are about half health or less, syndra ult though is a threat no matter you health if she has 4 or 5 balls, but when you are laning against syndra she is going to be using her Q to help last hit some minions and many times their jungler gives her blue buff then she is always have atleast 4 or 5 balls on the map at once. My suggested change, tweak, whatever you want to call it, Syndra ult only does extra damage if her balls are in a certain range of Syndra. This change would require syndra to actually think about what she is doing with her balls instead of just spamming and throwing them everywhere. Syndra ult can still do as much damage, but getting a 5 ball set up would require some actual using of the brain.
I think a good starting range for the ult ball criteria would be the max range of syndras stun. A small change like this could make it so playing against a syndra wouldnt be a nightmare 99% of the time. If you see syndra has 5 balls in lane stand further back so that you are in range of only 1 or 2 balls extra from her ult. If syndra lands a good stun you are still going to die most likely, but this could help reduce the: walks up and clicks R, part about syndra that frustrates many summoners.
If you have any Positive or constructive feedback feel free to leave a comment down below.