5.1 Syndra Nerfs
Might have been a little too harsh with the removal of DFG. Lemme explain
The reason Syndra was such a good pick was because she had a strong reliable lane phase, able to pressure hard, especially against melee champions. Because of this reliable lane phase, she was consistently able to pick up an early DFG and then either: A) kill her lane opponent, in which she would force pressure mid B) Roam and help snowball lanes C) Screw over the enemy jungler by camping routes and picking them off.
After she did one of the following, she would do what every other champion in League would do: Snowball. And with massive range and huge burst damage with an amazing CC, she would dictate a game in her favor. So yes, I agree she did need a small tweak, but with the removal of DFG, the nerfs are just too much now. Her lane phase early is significantly weaker, and with the nerf to Athenes, Morellos, and the removal of DFG, her early item options are limited, and it gives her a very, very unstable lane phase transition to mid game. With the reduced damage early (doesn't seem like much, but 30% is a lot) she can't quite pressure as hard as before (fair enough). The real problem comes in when she now has an awkward and quite frankly, awful itemization option.
-Athene's doesn't give her the mana regen she needs anymore (especially mid game, you run oom after 2 rotations during sieges) and if you position properly, the MR isn't really necessary -Morello's is a good item for her, but the increased cost means she has no kill potential (for a single target burst mage, its rough) until about level 9 where the Q damage nerf equals out, unless her lane opponent takes way too much harrass. -No DFG means you don't have the same incredible amount of pressure on your laner -Any other AP item, you will run oom just clearing a minion wave.
When Riot nerfed Syndra, I don't think they incorporated the Athene's nerfs, the morello nerfs and the removal of DFG. And now with the rise of manaless/energy champs, she becomes a niche pick rather than a general all around consistent pick.
But don't get me wrong, she was a little out of hand at first, but without DFG she just doesn't have the same oomph as before, and the nerfs just solidified that.