Vayne

Strengths

Tumble has many uses, but it cannot pass over walls.
Condemn can be used to both pin targets to walls to ensure a kill, or to escape a pursuer.
Don't go in first to a large teamfight. Wait for your teammates to initiate.

Passive · Night Hunter — Vayne ruthlessly hunts evil-doers, gaining Move Speed when moving toward nearby enemy champions.
Q · Tumble — Vayne tumbles, maneuvering to carefully place her next shot. Her next attack deals bonus damage.
W · Silver Bolts — Vayne tips her bolts with a rare metal, toxic to evil things. The third consecutive attack or ability against the same target deals a percentage of the target's max health as bonus true damage.
E · Condemn — Vayne draws a heavy crossbow from her back, and fires a huge bolt at her target, knocking them back and dealing damage. If they collide with terrain, they are impaled, dealing bonus damage and stunning them.
Ultimate · Final Hour — Readying herself for an epic confrontation, Vayne gains increased Attack Damage, Invisibility during Tumble, reduced Tumble cooldown, and more bonus Move Speed from Night Hunter

A suggested 5-lane lineup built around Vayne, based on hero partnerships and role synergy — not win rate.