Ancestors might
ancestors might is a mode where the power of the champions prior versions grant their power Each champion will be given the highest number each of their stats have ever had. from their hp to their attack speed to their run speed to their ad/ap ratios. This does not mean 1 iteration of the champion, so it isnt just when the champion was strongest, it is all of their iterations stats. If a champs hp was highest say 7 patches ago, and their ap ratios were best 2 patches ago, they get the best of both worlds, or in the grand scheme of things, best of many worlds, as champions have many many many numbers. this includes scaling, so hp per level, armor per level, mana regen per level, all count.