(Update Aug 28: Attack Speed Cap has been increased to 5 in TFT Patch 9.17. Previously it was capped at 2.5.
Update Aug 14: TFT Patch 9.16 didn’t bring any changed to Rageblade, so everything detailed below still applies.
Update Aug 7: Patch 9.15B Update – Rageblade now grants 5% per stack, up from 4% in previous patch. You can read full TFT Patch 9.15B notes here.)
If you played or watched a few dozen TFT games, you’ve probably seen Kassadin, Vayne, Varus or Volibear with 2 Guinsoo’s Rageblade on them.