Nidhoggmon - Need just 1 memory

The 1 memory we need is to digivolve from LV3 to LV4. There is some cheap 1 cost to digivolve LV4 digimon in green color, example in this post is [BT4-053]Roachmon, then use a download LV5 to save 3 costs that needed for digivolving from LV4 to LV5. For this step, you can choose either Blossomon or Argomon, they are both LV5 download digimon. You can rest itself (this digimon) or rest another LV3 digimon for download effect (Nidhoggmon effect is triggered during digivolving, it does not need to stay in active mode). At the end, we can use the option card Hidden Potential to digivolve from LV5 to LV6 Nidhoggmon without paying any cost (Green is so unfair).