Nice guide, but I think ghost will be better than flash on Yi. Flash does not synergise with any of Yi's spell. (synergy being one helps the other). Ghost and Highlander creates a great synergy. (Ghost makes highlander runs faster while Highlander prevents your 27 percent movement speed ghost bonus from being slowed) imagine a ghost that can not be slowed. You might argue flash can help you escape. But if you need your summoner spell to escape the situation, you probably shouldn't be in the situation in the first place. With faster running speed from ghost. you spend less time chasing. means you will land hits more frequently on escaping enemy champ. since Yi only has 12 second burst, you want to land as many hits as you can during that 12 sec. I hope i made my point here.