In the Tri-Monster Memo minigame the board holds 27 face-down cards: 9 monsters with 3 cards each. Each round you flip 3 cards, and three identical ones stay face up. The reward depends on the number of rounds: gold chest up to 16, silver 17–24, bronze from 25. You have 10 seconds per card, and two hints (for 3 and 5 trio cards) briefly show the whole board.
The helper remembers every flipped card and computes exactly (no simulations) which card to flip now for the best chance of the gold chest. Following the suggestions with perfect memory, you get the gold chest in about 85% of games. The helper also tells you when to use a hint to make gold certain.
The gold chest is for finishing within 16 rounds, silver for 17–24, bronze for 25 or more. A round is flipping 3 cards, even when they make no trio or the game flipped a card after 10 seconds. You can then upgrade the chest for yang, up to VIP.
Start every round with an unknown card. Take a known card only when you know where both other cards of that monster are; otherwise flip another unknown one, which gives the same trio chance and new information on a miss. This single rule raises the gold chest chance from about 32% to 85%.
A hint shows all cards, so afterwards every round is a trio. You only need it when the rounds left to your goal equal the trios still missing; earlier it just costs trio cards. The helper shows this margin all the time.