If you go full Movement speed (Any Lost Chapter item to start), Dark Seal -> Mejai's, Cosmic, Stormsurge, Lich bane, Symbiotic or Swifties for boots you can roam from a crashed wave, to another lane, and back before the next wave fully dies. If you're willing to subsidize wave gold +hexcore for kill gold+hexcore and don't care about any form of armor or real AP, you can go full movement speed and full roam. Speed up your roam with Upgraded Q, and clear waves easily with upgraded E. Only tested in practice game, play at your own discretion. Switch out one of the other items for Hextech rocketbelt if you really want to turn Viktor into an assassin.