Here is the full list of all 27 Skulls of the Shogun achievements.
Win an online match that lasts at least 30 rounds, defeating at least 30 enemies.
Have an emblem upgraded to Gold status.
Complete every level such that your best times for all of them add up to less than 4 hours on Normal difficulty.
Acquire 100 emblems.
Earn all 72 of the Bone-A-Fide Edition Gold Skulls.
Defeat a General with a Tanuki taunt.
Win a multiplayer match with a 20-second-per-turn time limit.
Break a Deadly Alliance in online multiplayer.
Knock 3 foes off a ledge at once with a Demon Crow Monk's Typhoon spell.
Earn 60 gold skulls.
Complete the Forbidden Islands with 10 units or more.
Win a 4-player online multiplayer match.
Defeat 5 foes at once with a Salamander Monk's Lightning Storm spell.
Earn 30 gold skulls.
Complete the Forbidden Islands on Normal difficulty.
Win a team deathmatch game with your teammate still alive.
Win an online multiplayer match.
Complete the Land of Frozen Fortunes on Normal difficulty.
Acquire your first "Very Rare" emblem.
Complete the Land of Golden Harvest on Normal difficulty.
Earn 15 gold skulls.
Bring back a fallen unit with a Demon Fox Monk's Revive spell.
Complete the Land of Monsoon Meadows on Normal difficulty.
Complete the Land of Eternal Blossoms on Normal difficulty.
Defeat an enemy Monk by haunting its Shrine.
Complete the Shores of the Dead on Normal difficulty.
Power up your General to a Demon.