From my experience, Umbreon and Espeon Happiness evolutions were totally replaced. To make matters worse, most if not all new evolution items are available only in a limited quantity. Add another aggravating factor: due to TM shuffling, some TMs like the important Flash is now also limited (can't buy at Goldenrod anymore), which means you can't stock on Flash TMs to use it on the fly then switch back to your Thunderbolt immediately via TM or something (to save space from HM slaves).
All that said, there are 2 good ways I've found to solve all this:
1-) Pokegen x99 of all new evolution items/stones and the Flash TM (list below).
2-) On the documentation included with Sacred Gold, there is 1 Ar Code PDF. With the game ID found in there you can use the ALL AR Codes for vanilla HGSS in this mod (shiny, EVs, etc), all you have to do is to copy and paste HGSS ar code folder in R4CCE and change the ID to match (read below).
1a) For method 1, pokegen/sav the following items in your bag or something:
Woodland Ore = Journal x99.
Chilled Ore = Old Charm x99.
Voltaic Ore = Member Card x99.
Aubade Orb = Works Key x99.
Serenade Orb = Seal Bag x99 (Umbreon).
Covenant Orb = Secret Key x99.
Flash is Flash. lol
2a) For method 2, use this code already available for vanilla HGSS R4CCE cheats database:
Inside folder "Hexic's Misc Codes", code "Modify Item/Cost/Sell in Poke Mart [CherryGrove (Fly!)".
How to use: activate code, log into the game. Press " L + R ", this will give you 536 master balls and something like 99 Ultra and Great balls. They work as placeholders to modify what is sold at Cherrygrove Pokemart. Essentially, Ultra and Great balls means the buy/sell price, so if you discard 98 of each, whatever you're trying to buy/sell x99 will cost only 99 Poke Yen.
Master balls are digits defining which item you get if AND ONLY IF you hold " L " while buying at that specific market. Discard enough Master Ball until it matches the digit of the item you want:
Covenant Orb = 467
Voltaic Ore = 454
Chilled Ore = 439
Aubade Orb = 438
Serenade Orb = 436 (Umbreon)
Woodland Ore = 433
Flash TM = 397
If you do in the EXACT ORDER mentioned above, 536 Master Balls will be enough to get all items x99 in 1 go. If you screw the order you can always press " L + R " again to replenish 536 Master Balls and those Ultra/Great Balls.
NOTES:
Method 1 is faster. Requires PC.
Method 2 have 2 distinct advantages: 1-) Portability: you can use it on the fly (flashcards) and 2-) Permanent solution: If you modify Hexic's original code and change the Hex value that adds Master Balls to your inventory to match each item above, you can create specific codes for each of those items and name the codes accordingly so that you never have to look those digits up ever again, even if you restart your save file or decide to play 10 years from now and forgot all about these digits. For reference, 536 converted to Hex is 218 so look for that if you want to change Hexic's code. The other numbers converted to hex:
Covenant Orb = 1D3
Voltaic Ore = 1C6
Chilled Ore = 1B7
Aubade Orb = 1B6
Serenade Orb = 1B4
Woodland Ore = 1B1
Flash TM = 18D
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