Challenges and Requirements

(Originally posted by Mortal95)

I had this idea of listing challenges till now (and in upcoming days) with only tower requirements for easy reference though we have a Separate database of all challenge characters and requiements and list of opponents and their stats we face in each tower.
The challenges and their dates were taken from MKX Mobile Event History by @TOASTY_3DX (Thanks a lot)
The list include Challenge Characters in their order and their first appearance (duration) and Tower 4 and Tower 5 requirements as requirements of Towers 1,2,3 remain same for all challenges (Only Bronze, Bronze and Silver and Only Silver respectively).
Hope you guys find it useful!
P.S. Please correct if there is any discrepancies.

Thunder God RAIDEN (TGRd) - 12.06.15 to 29.06.15
Tower 4 - A SO character on team
Tower 5 - A MA on team

Flaming Fists LIU KANG (FFLK) - 9.07.15 to 29.07.15
Tower 4 - An OW character on team
Tower 5 - D'Vorah (Any variation)

Piercing MILEENA (PMl) - 30.07.15 to 19.08.15
Tower 4 - A MA on team
Tower 5 - Kotal Kahn (Any variation)

Heavy Weapons JAX BRIGGS (HWJB) - 20.08.15 to 09.09.15
Tower 4 - A SO character on team
Tower 5 - Johnny Cage (Any variation)

Kold War SONYA BLADE (KWSB) - 10.09.15 to 30.09.15
Tower 4 - A MA character on team
Tower 5 - Kano (Any variation)

Gunslinger ERRON BLACK (GsEB) - 01.10.15 to 21.10.15
Tower 4 - An OW character on team
Tower 5 - Kung Jin (Any Variation)

Unstoppable JASON VOORHEES (UJV) - 29.10.15 to 18.11.15
Tower 4 - OW team
Tower 5 - Sonya Blade (Any variation)

Ronin KENSHI (RKe) - 19.11.15 to 09.12.15
Tower 4 - A SO character on team
Tower 5 - Ermac (Any variation)

Dark RAIDEN (DRd) - 10.12.15 to 06.01.16
Tower 4 - Only Gold Tier Characters
Tower 5 - Jax Briggs (Any variation)

Revenant KUNG LAO (RKuL) - 07.01.16 to 27.01.16
Tower 4 - Only Female Characters
Tower 5 - Cassie Cage (Any Variation)

Dark Empress KITANA (DEKt) - 28.01.16 to 18.02.2016
Tower 4 - A NR character on team
Tower 5 - Reptile (Any variation)

Undead Hunter JOHNNY CAGE (UHJC) - 19.02.16 to 03.03.2016
Tower 4 - MA team
Tower 5 - Kenshi (Any variation)

Kraken REPTILE (KrRp) - 10.03.16 to 31.03.16
Tower 4 - OW team
Tower 5 - Sub Zero (Any variation)

Bone Shaper SHINNOK (BSSh) - 31.03.16 to 21.04.16
Tower 4 - SO team
Tower 5 - Scorpion (Any variation)

Dark Lord KOTAL KAHN (DLKoK) - 02.06.16 to 23.06.16
Tower 4 - SO team (Gold tier)
Tower 5 - Johnny Cage (Any variation)

Marksman KUNG JIN (MKJn) - 23.06.16 to 14.07.16
Tower 4 - OW team (Gold tier)
Tower 5 - D'Vorah (Any variation)

Klassic KANO (KKn) - 14.07.16 to 04.08.16
Tower 4 - MA team (Gold tier)
Tower 5 - Kitana (Any variation)

High Tech JACQUI BRIGGS (HTJqB) - 04.08.16 to 25.08.16
Tower 4 - Gold tier characters
Tower 5 - Ermac (Any variation)

Kold War SCORPION (KWSc) - 25.08.16 to 15.09.16
Tower 4 - NR team
Tower 5 - Jacqui Briggs (Any variation)

Cyrax TRIBORG (CTg) - 15.09.16 to 22.09.16
Tower 4 - OW team (Gold tier)
Tower 5 - Commando Kano

Smoke TRIBORG (STg) - 22.09.16 to 29.09.16
Tower 4 - Only Female characters
Tower 5 - Venomous D'Vorah

Sektor TRIBORG (STg) - 29.09.16 to 06.10.16
Tower 4 - NR team
Tower 5 - Bojutsu Kung Jin

Pharoah ERMAC (PEr) - 06.10.16 to 20.10.16
Tower 4 - MA team (Gold tier)
Tower 5 - Master of Souls Ermac

Day of the Dead KITANA (DDKt) - 20.10.16 to 03.11.16
Tower 4 - OW team
Tower 5 - Sun God Kotal Kahn

Nightmare FREDDY KRUEGER (NFK) - 15.12.16 to 05.01.17
Tower 4 - SO team
Tower 5 - Kung Lao (Any variation)

Kold War SUB ZERO (KWSZ) - 05.01.17 to 26.01.17
Tower 4 - SO team (Gold tier)
Tower 5 - Tactical Sonya Blade

Klassic SONYA BLADE (KSB) - 26.01.17 to 16.02.17
Tower 4 - Gold tier characters
Tower 5 - Noxious Reptile

Elder God KENSHI (EGKe) - 16.02.17 to 09.03.17
Tower 4 - MA team
Tower 5 - Sub Zero (Any variation)

Tournament QUAN CHI (TQC) - 16.03.17 to 30.03.17
Tower 4 - SO team
Tower 5 - Kitana (Any variation)

Sub Zero TRIBORG (SZTg) - 30.03.17 to 13.04.17
Tower 4 - MA team
Tower 5 - Scorpion (Any variation)

Scourge BARAKA (ScBk) - 04.05.17 to 18.05.17
Tower 4 - OW team
Tower 5 - Liu Kang (Any variation)

Treacherous TANYA (TTn) - 18.05.17 to 01.06.17
Tower 4 - MA team
Tower 5 - Jacqui Briggs (Any variation)

Assassin JADE (AJd) - 01.06.17 to 15.06.17
Tower 4 - SO team
Tower 5 - Kitana (Any variation)

Shirai Ryu TAKEDA (SRTk) - 14.09.17 to 28.09.17
Tower 4 - MA team
Tower 5 - Sub Zero (Any variation)

Vengeful SHINNOK (VSh) - 28.09.17 to 12.10.17
Tower 4 - SO team
Tower 5 - Johnny Cage (Any variation)

Tigrar Fury GORO (TFGo) - 12.10.17 to 19.10.17
Tower 4 - MA team
Tower 5 - Raiden (Any variation)

Aftershock TREMOR (ATr) - 02.11.17 to 16.11.17
Tower 4 - OW team
Tower 5 - Mileena (Any variation)

Punk CASSIE CAGE (PCC) - 16.11.17 to 23.11.17
Tower 4 - OW team
Tower 5 - Reptile (Any variation)

Kosplay Jacqui Briggs (KpJqB) - 21.12.17 to 28.12.17
Tower 4 - MA team
Tower 5 - Kung Jin (Any variation)

Dragon Breath BO RAI CHO (DBBRC) - 08.03.2018 to 15.03.2018
Tower 4 - SO Team
Tower 5 - Kenshi (Any Variation)

Hanzo Hasashi SCORPION (HHSc) - 15.03.2018 to 22.03.2018
Tower 4 - NR Team
Tower 5 - Sonya Blade (Any Variation)

Shokan Warrior KINTARO (SWKro) - 22.03.2018 to 29.03.2018
Tower 4 - OW Team
Tower 5 - Kano (Any Variation)

Shaolin Fist KUNG LAO (SFKuL) - 07.06.2018 to 14.06.2018
Tower 4 - MA Team
Tower 5 - Liu Kang (Any Variation)

Kombat Cup JOHNNY CAGE (KmCJC) - 21.06.2018 to 28.06.2018
Tower 4 - NR Team
Tower 5 - Cassie Cage (Any Variation)

Kombat Cup SONYA BLADE (KmCSB) - 28.06.2018 to 05.07.2018
Tower 4 - OW Team
Tower 5 - Jax Briggs (Any Variation)

Klassic Ermac (KEr) - 23.08.2018 to 30.08.2018
Tower 4 - SO Team
Tower 5 - Quan Chi (Any Variation)

Ronin Kitana (RKt) - 20.09.2018 to 27.09.2018
Tower 4 - MA Team
Tower 5 - Mileena (Any Variation)