Singed is a really big counter to all the meta champions like Kayn, Elise, Pyke, Irelia etc... Anyone that uses one or multiple dashes as a core part of their kits is gonna get absolutely rekt if singed hits them with his "w". For example: Kayn can't neither Q,W nor R if singed touches him. If he manages to escape your "w" you'll just have to "e" him when he goes into a wall so he gets stunned and comes back at you.

Against a ranged champ u can't really do anything before you're 3. Against melee champs it's another story.You wanna stay in fight 24/7 so that u can always proc your grasp. Take short trades until you know you can kill the ennemy.Don't push when you're opponent when he's lane unless you want to roam (better after 6).You can 1v1 many champs as nasus(even with his ult), darius if you're smarter then him, irelia,..... If you just get 1 kill, you can push, get plates , proxy minions, roam, get an early riley so no one can escape you nor chase you.

Your "e" will be used either as engage or disengage, you can protect you carries from a j4 with it or you rcan rush the ennemy ad carry and throw him into your team. When you combine r with ghost, no one can escape you. Your goal is to poison as much ennemies as possible.Sometimes you can just solo kill their adc in the middle of 4 ennemies and then just go out or kill the others.

Get ocean drake. Get cloud drake. Don't hesitate to roam and even go teamfighting but don't forget you can kill a minion wave pretty fast as you're one of the best pushers and can win 1v2, 1v3 situations.

Don't be too previsive. If renek knows you're going to "w" him and that he dashes at the same time you channel "w", he's already stunning you and hitting you hard in the face.Same for irelia,....