-Uradora are revealed every round

-One of each number tile is akadora
 
Hakurei Reimu: Anti-ron barrier for 6 turns
 
Kirisame Marisa: Turns all tiles of a random value in her hand into akadora
 
SDM: Tsumo wins are worth double
 
Rumia: Hides her side of the table in a cloak of darkness
 
Daiyousei: Can redraw her starting hand
 
Cirno: Freezes a random player for 4 turns, forcing them to discard whatever they draw
 
Hong Meiling: Makes herself the dealer to start with
 
Koakuma: Can redraw 3 tiles from her hand at the start of a round
 
Patchouli Knowledge: Less likely to draw wind tiles for the rest of the round
 
Izayoi Sakuya: Switches 3 tiles from her hand with the wall
 
Remilia Scarlet: Turns tiles from 1 through 4 in her hand into akadora
 
Flandre Scarlet: High chance of drawing wind tiles for the next 6 turns
 
Hakugyokurou:
            -No akadora
            -Special abilities charge slower
 
Letty Whiterock: Freezes for two turns the next player who calls pon
 
Chen: Adds an additional 2 han when calling riichi
 
Alice Margatroid: Halves the winning hand if it exceeds 12,000 points
 
Lily White: Exchanges Haku tiles for discarded tiles
 
Lunasa Prismriver: Removes a dora indicator from play
 
Merlin Prismriver: Flips over the next dora indicator
 
Lyrica Prismriver: Exchanges a random tile from her hand for a discarded tile
 
Konpaku Youmu: Blocks all chi, pon, and kan for 2 to 6 turns
 
Saigyouji Yuyuko: Takes 1000 points from the player she calls pon on
 
Yakumo Ran: Increased chance of drawing winning tile during riichi
 
Yakumo Yukari: Removes the next 8 tiles in the wall from the game
 
Eientei:
            -No extra points for ippatsu
            -No kandora or uradora
 
Wriggle Nightbug: Exchanges a random tile in her hand with the first dora indicator
 
Mystia Lorelei: Hides the entire table for 6 turns
 
Kamishirasawa Keine: Reduces another player’s magic meter to zero
 
EX Keine: Reduces all other players’ magic meters to zero
 
Inaba Tewi: High chance of getting uradora when winning with riichi
 
Inaba Reisen: Turns all akadora in play into regular tiles
 
Yagokoro Eirin: Draws only manzu tiles for five turns
 
Houraisan Kaguya: Draws only dora tiles if able for the next 3 turns
 
Fujiwara no Mokou: Can rule at the start of a round that any hand under mangan is worth nothing
 
Muenzuka (Unlocked with the Tenshi group)
            -Points are only lost, not gained
            -Riichi costs nothing
            -No akadora or open tanyao
 
Shameimaru Aya: Takes another turn, the tile from the first turn can’t be stolen
 
Himekaidou Hatate: Selects a tile in her hand, then the next time she draws a tile it will be that one. It won't be an akadora and she cannot call riichi, tsumo, or kan immediately after drawing it
 
Kazami Yuuka: Increased chance of getting kandora
 
Medicine Melancholy: Decreases magic meters of players who lost points and prevents them from being refilled next round
 
Onozuka Kamachi: Decreases random opponent’s magic meter
 
Shikieiki Yamaxanadu: Increases noten payments twofold
 
Youkai Mountain:
            -No special abilities
            -No open tanyao
            -There is never a two-han minimum
 
Moriya Shrine:
            -No akadora
            -Your seat wind is always a dora tile
 
Aki Shizuha: Prevents uradora from being flipped
 
Aki Minoriko: Adds 30 fu to her hand, or 40 fu if tsumo
 
Kagiyama Hina: When she calls ron on someone, that player will get a very bad starting hand next round
 
Kawashiro Nitori: Discards tiles face down for the next 6 turns
 
Inubashiri Momiji: Senses if other players are in tenpai
 
Kochiya Sanae: Ensures her next starting hand will have 3 of a wind tile
 
Yasaka Kanako: Ensures her next starting hand will have 7 different tiles in the same suit
 
Moriya Suwako: Turns some of her tiles into souzu
 
Palace of the Earthly Spirits:
            -Ron wins are worth double
            -If the dealer is leading in points, she plays with her hand revealed
 
Kisume: When she calls ron on someone, that player must discard her next 3 draws next round
 
Kurodane Yamame: Binds a tile to an opponent’s hand permanently
 
Mizuhashi Parsee: Removes 2 han from the winning hand
 
Hoshiguma Yuugi: Doubles her winning hand’s score when she wins a round
 
Komeiji Satori: Can see everyone’s starting tiles, ones drawn after are hidden
 
Kaenbyou Rin: Exchanges a tile in her hand with a discarded tile
 
Reiuji Utsuho: Raises chances of having 4 of a tile in her starting hand next round
 
Komeiji Koishi: Protects her tiles from being stolen by chi, pon, and kan
 
Myouren Temple
            -No akadora
            -Fu is doubled except for the 20 base fu
            -When the player in last place wins a round, she gets double the points

Nazrin: Ability can only be used when she draws her first tile. Once she enters tenpai this round, for the next five turns, she has a high chance of drawing her winning tile, as long as she hasn’t called riichi.

Tatara Kogasa: Adds 2 han to a closed non-riichi hand, or 3 han if tsumo

Kumoi Ichirin: Erases her first 6 discarded tiles

Unzan: Trades opening hands with a random player

Minamitsu Murasa: Much higher chance of drawing winning tile once there’s 4 or less tiles left in the wall. Tile will be created if it’s not already there. Ability can only be activated when there’s 12 or more tiles left in the wall.

Toramaru Shou: Her starting hand next round will have at least 1 or 2 akadora in it

Hijiri Byakuren: Trades a tile in her hand for any tile from an opponent’s discard pile. Cannot be used on the first turn. She may not call kan or tsumo immediately after using this ability.

Houjuu Nue: Disguises the suit of all opponent’s tiles for everyone except herself for 6 turns
 
Cemetery: When the dealer wins a round, she gets double the points
 
Kasodani Kyouko: The next tile she draws will be the same tile she just drew, if possible. It won’t be an akadora, and tsumo, riichi, and kan can not be performed immediately after drawing it.
 
Miyaku Yoshika: Steals 500 points from each player, plus extra points the more open sets that player has
 
Kaku Seiga: Furiten does not apply this round
 
Soga no Tojiko: She can only activate this ability when she draws her first tile. If she wins the round, the dora indicated by the first dora indicator is worth double.
 
Mononobe no Futo:  Her starting hand next round will have one of each wind tile
 
Toyosatomimi no Miko: Until she draws her next tile, no one can win or call riichi
 
Futatsuiwa Mamizou: Selects three tiles from her hand, then if anyone else has any of those tiles in their hand, she can see those tiles in their hands for the rest of the round. Tiles drawn afterwards will not be revealed.
 
Stage of the Heavens (Unlocked with the Tenshi group)
            -Start with 5 million points
            -Aotenjou scoring rules
 
Ibuki Suika: Exchanges an odd tile for an even one
 
Nagae Iku: All 1-3 han yaku are increased by 1 han, except Riichi, Pinfu, Double Riichi, and Yakuhai (ron)
 
Hinanawi Tenshi: Changes each tile in her hand to the next value up
 
Kourindou (CDs and manga)
            -Any hand worth less than 8000 points is worth nothing
            -Riichi is worth 2 han and Double Riichi is worth 4 han
 
The Human Village
            -Only for 3-player mahjong
            -Honor tiles are not used
            -Calling chii is allowed
 
Usami Renko: Imposes a 5-second turn limit
 
Maribel Hearn: Cancels all active magic powers
 
Hieda no Akyuu: Sees her next 6 draws for 3 turns
 
Sunny Milk: Places down a zero-commitment riichi stick
 
Luna Child: Can call chii on anyone for a turn
 
Star Sapphire: Marks the winning tiles of players in riichi
 
Morichika Rinnosuke: Marks all dangerous tiles for one turn
 
Watasuki no Yorihime: Returns an open pon to her hand
 
Watasuki no Toyohime: Returns an open chi to her hand
 
Reisen: Scores this round as a tsumo
 
Ibaraki Kasen: She can activate this ability when calling riichi and only if she is in 2nd place or lower. If she wins by tsumo, the player in 1st place must pay all of the points.
 
Twilight Bar (Uwabami Breakers)
            -Points are only gained, not lost
            -Aotenjou scoring rules
 
Asama Isami: She can activate this ability when she wins the round, and she gets an extra 1500 points for each honba counter (This is how it works in 2nd generation, I couldn’t figure out exactly how it works in 3rd generation but it seems pretty close)
 
Hakkaisan Tatsumi: Activated when winning. 1-sou and 9-sou tiles become akadora.
 
Arie Rumi: Her next starting hand will have somewhere between 0 to 2 concealed triplets
 
Amakasu B. Tenji: Gets an extra 600 points for each souzu tile
 
Jun’ya Outa: Gets an extra 600 points for each pinzu tile
 
Maybell: Steals 2000 points from any player who uses their special ability this round
 
Arioch: Up to four random tiles in her hand become akadora; the fuller her opponents’ magic meters are, the more akadora she gets

Makai (PC-98)
            -Magic gauge increases faster
            -BUT: special abilities cost 1000 points to use; the points go to whoever wins the round
            -No akadora
 
Mima: Receives a pair of sangenpai in her opening hand next round
 
Shinki: All 1-3 han yaku are increased by 1 han, except Riichi, Pinfu, Double Riichi, and Yakuhai (tsumo)
 
PC-98 Alice: Receives more tiles of a certain suit in her opening hand next round
 
Asakura Rikako: Ability can only be used when she draws her first tile. For the rest of the round, whenever another player draws an indicated dora tile (akadora don’t count), she must discard it immediately
 
Okazaki Yumemi: Can switch all terminals in her starting hand for simples
 
Kitashirakawa Chiyuri: Can switch out all honor tiles in her starting hand for other tiles
 
PC-98 Yuuka: Increased chance of getting kandora (same as regular Yuuka)