Lethality Rek'Sai Build

General

1. You build Lethality and wait for a moment to strike enemy squishes.
2. Snowball / Mark is a crucial cooldown for playing this build. Do not waste it or even wait to hit the enemy at point-blank range to ensure hit (so you follow them, if they Flash).
3. If an enemy team is full of tanks or bruisers, rush Serylda's Grudge or even Lord Dominik's Regards early (sometimes even #2). Black Cleaver is also an alternative. The key is to adapt to the enemy team.
4. This build revolves around Hail of Blades and Lethality short bursts of damage.

Champion

1. You can use your Void Rush (R) for survivability and disengage. Getting focused really hard in the fight? Use it, so enemies will lose target, stop attacking you, so then you can run away.
2. You can use your Queen's Wrath / Prey Seeker (Q) (when burrowed) to scout bushes.
3. You will detect enemies moving in the bushes thanks to Burrow / Un-burrow (W) (passive part while burrowed).
4. Your ally got hit with a Snowball? Burrow and go close to them, to knock them up when they arrive. You can even time it to knock them in the air. Often it will be certain death for enemy player.

Riot

1. Keeping tunnels spread out across the map will ensure you have choices when you want to cast Void Rush.
2. Cast Burrow before travelling around the map to take advantage of the increased Move Speed and the safety provided by Tremor Sense.
3. Tremor Sense can warn you of enemies closing in, and is particularly useful when entering enemy territory.