As of their most recent 1v1 battle, Mugi is running Wall Breakers, Magic Archer, Bats, Miner, Fire Spirit, Skeletons, The Log, Bomb Tower at 2.4 average elixir. It's read straight from their official battle log and refreshes periodically.
Yes — Mugi's player tag is verified against the official Clash Royale API, and the deck above is their most recent 1v1 lineup from that same API. Nothing is estimated.
