UPDATE 08/20/2023
Came in 3rd place this time at Gamers Alley's Store Championship tournament. The fact that this deck is consistently making Top 4 speaks for itself, especially in the current BT13 format. Will be attending the second Store Championship at this store to try again and do better.
UPDATE 08/13/2023
Won Imperial Comics Store Championship.
Match-Ups
2-1 Guilmon Mill
2-0 Jesmon
2-1 Belphemon
Only a 10-Player Tournament. Match-Ups were tight, but having the match-up knowledge and proper plays won me the day. "Ordinemon" just wins games.
Guilmon-Mill deck was a learning curve. Had to be more mindful of when to recover and when to digivolve in order to maintain as much cards in deck. Rookie/Champion rush won me the match-up by game 3. Jesmon is a bad match-up, but this deck can get its set up fairly quick and faster before the opponent decides to push out of raising. First-Turn Mirei plays and Gatomon set ups in raising ensured I got out a Mastemon by my third turn and enabled me to control the board and ultimately going into the Ordinemon to mop up the rest of the Sistermon and single Jesmon tower off the board to get a HUGE security lead. Jesmon can't really protect itself from deletion effects outside of the Sistermon Blanc's Decoy and Mastemon/Lucemon Chaos Mode can easily deal with her as well as the Blanc/Blocker to ensure we get our security checks in. Starter Deck Angewomon also helps slow down potential extra checks if a Flame Hellscythe is triggered in security.
Belphemon is a pretty favorable match-up as long as you see a Psychemon starting hand or early in the game. Prevents the opponent from making those extra plays with reducing the play cost of Gizmons. Slowing their game plan is the way to beat this match-up. Starter Deck Angewomon also wins you the game since you can still target the Belphemon: Sleep Mode with the "-2 Security Checks until the end of the opponent's next turn" effect which results in rendering the Rage Mode completely useless their following turn. Opponent isn't going to want to attack while you also have Blocker presence with Retaliation during their turn.
UPDATE 06/08/2023
New ratio for a much more balanced consistency. Also keeping in mind the "Hunters/Xros Heart" match-ups. Play Tests have also yielded satisfactory results against the BWG/Raid Grey match-ups as well. Still no protection against Chaos Degradation and be mindful of when to Flame Hellscythe. New cards like the BT12 Greymon makes players want to evo out on the board to set up Tai Tamers and at that point, they're sitting ducks. Control the board better by deleting/DP Reducing their smaller Lv.4 and Lv.5 lines before they get the chance to get to their top end. Early game, if they don't have a Yuuya set up already, you will have no problems controlling the board with option cards. Maintain lead by constantly having the Blocker/Retaliation "during opponent's turn" to constantly force them to strip sources to prevent deletion if they choose to attack. Giving you ample opportunity to clean up the following turn. Most games, Greymon decks will rarely ever have more than 1 perfect line with the X-Antibody line for protection. Just maintain early-game control and the match-up is easily won.
UPDATE 05/08/2023
Only new adjustsment are really the Lv.3's. Flood-gates like Gazimon are pretty much useless now in a meta riddled with "Beelzemon X" decks that can easily delete them with low cost options like Death Slinger or even off of inherit skills such as the starter deck Impmon. Opted to replace them with BT4 Lucemon to incur more recovery. Honestly, Mastemon has been knocked down to a solid tier-2 deck in the BT12 meta in my opinion. It has good match-ups against certain decks, but takes a lot of high-skill, zero mistake plays against others just to win. Beelzemon, Raid Grey, Hunters can out right just out speed you or shut you down.
UPDATE 03/05/2023
Venusmon was a fun tech for a bit, but I honestly prefer the BT3 Mastemon more. Really helps close out games more consistently. You can also opt to use a second copy of Ophanimon: Falldown Mode for more recovery.
My build of BT11 Mastemon. All about rushing out Mastemon as soon as possible and maintaining board control. Venusmon works surprisingly very well with the BlackWarGrey X match-up.
BT11 Mastemon is definitely a higher skill level deck. Not recommended for beginners. Little room for error plays.