My two thoughts about changing how DClone spawns:
1: Local game walk
SoJ sale has 33.3% chance of spawning DClone, and only in that game. If the first one doesn’t spawn him, the next SoJ has a 66.6% chance. If still no spawn, the third SoJ is 100%. (Same game, if you leave and restart, it resets back to 33%)
or…
2: Regional/global walk
Get rid of the counter. Dclone needs to sneak up on us. Maybe just change it to a periodic “SoJ’s sold to merchants” if SoJ’s are being sold.
0.13888%, or 1 out of every 720 walks = Base chance of Dclone walking for everyone regionally/globally when enough SoJ sales pop him. No SoJ sales required. If you sell SoJ’s, you boost your chances of getting him to spawn.
IF HE DOES NOT SPAWN FOR YOU OR YOU MISS THE WALK, you get to keep your upgraded chance.
IF HE DOES SPAWN FOR YOU, your chance is reset back to the base chance. (regardless if you kill him or not)
1:720 or 0.13888% = Base chance.
1:120 or 0.8333% = Sell 1 SoJ.
1:24 or 4.1667% = Sell 2 SoJs.
1:6 or 16.667% = Sell 3 SoJs.
1:2 or 50% = Sell 4 SoJs.
1:1 or 100% = Sell 5 SoJs.
Edit: One additional thought on regional/global, if in a multiplayer game, only the base chance applies. Each additional party member in the game increases the base chance by 25% multiplicatively, so an 8 player game would be a 0.66% chance of him spawning.
Your upgraded chance only applies in solo games and would not be lost if Dclone walks in a public game with other players.