Kassadin is a midlaner Assassin-mage Champion with a lot of mobility due to his R, especially in the late game. your goal is usually surviving the hard landing phase to be as effective as possible in the mid and late game. This guide was made by N0EG0, a %70wr Masters main, and in it you're going to learn how to itemize, what to max, and to deal with some of the hard matchups!

Pros:

Kassadin's passive, Void Stone, allows him to take less magic damage making him strong into Ability Power-based champions.

Although he is a scaling champion, Kassadin can dominate games from the early stages and snowball the game if done correctly.

Cons:

Having low base defensive status, Kassadin can be weaker against AD lane bully champions.

You rely on both EXP and Items at the same time which can be exhausting in a way or another.

EarlyGame:
Your main goal is not losing lane to a point causing you to be completely out of the game unable to even scale. you mostly want to survive lane even if you had to give some resources until you at least get level 6, as then u get a very reliable amount of moblitiy.

MidGame:
At this point you should aim on being active on the map while keeping a good amount of CS/PM and not fall behind in exp.

LateGame:
You have probably gotten your items and reached the required Spikes to 1v9. Choose your target correctly and make as much use out of the mobility provided by your Ultimate as much as possible. Going in, taking a priority carry target on the enemy team, getting out is your optimal choice, but keep in mind some times taking a 1 for 1 or 1 for 2 can be a game winning play, so do not only play for KDA!