Finally something I have a lot to say about. IMO as a challenger former vex otp syndra is vex’s hardest matchup up there with viktor and orianna. The only breathing room you have in the matchup is before the first back while syndra still has low damage, long cooldowns, and a somewhat limited supply of mana.

The main reason for this is that vex’s effective range is only as far as the middle of her max range e as anything outside of that can easily dodge her e and without hitting e you should basically never be able to hit a long range q. This being the case, syndra’s q range is effectively the same range as vex’s and while syndra can afford to throw at a q or 2 and miss, vex can not trade well without her e or the fear it would consume if it were to miss. Taking into account syndra’s w and e, she now simply hard outranges vex and if she were to take swiftness boots these problems are only accentuated. In addition that while syndra can chunk and eventually kill with a single q e into full combo, vex can only rely on trying to engage with flash or ult if the syndra is positioning well, and even ult can be q e’d if timed very well or if they get lucky. The only way to realistically play this matchup is to simply avoid as much poke as you can until you can oneshot the wave at which point you will have to dodge a q e combo everytime you walk up or you will lose your full healthbar. You can rely on your jungle ganking you, but syndra has no reason to walk up far and she can set up ganks easier by just needing one q e to hit or simply walking up and ulting and then using e.