Some notes on future second stage Pokémon

The most important thing about second stagers is that they are the primary majority of Pokémon. This means that bulk of the changes will affect them, and not others. This seems rather paradoxical, as compared to third and single stagers, second stagers have been affected with power creep the least. This doesn't mean they are reliable enough to be unaffected by them, as shown by the abundance of Mega Evolutions in this group. Rather, because they are so large, the power creep has affected the bottom and middle more than the upper point. To illustrate this;

Gen I: Arcanine is the strongest, with 555 BST. (455 originally, shared with Exeggutor).

Gen II: Espeon and Umbreon are the strongest, with 525 BST.

Gen III: Milotic is the strongest with 540 BST.

Gen IV: Tangrowth is the strongest with 535 BST.

Gen V: Archeops is the strongest with 567 BST.

Gen VI: Noivern is the strongest, with 535 BST.

Gen VII: Silvally is the strongest with 570 BST.

As seen here, radical increase has not been seen for a long time. This is because the intermediary spaces have been filled in, rather than the top. In the recent generations, bottom have been made more powerful, with Chimecho increasing from 425 to 455, Medicham getting a Mega etc.

So, what will happen to the top, then? Well, with both single and third stagers experiencing power creeps, the bottom for two stagers is becoming less sustainable. So, the bottom barrier will increase further, with retcons. And the top? We will likely see more members there. When we will see further push beyond 540 barrier? Well, probably after third stagers do that. Otherwise, we don't need much to do there.

This means that the borders of conventional archetypes will be redrawn, but the ultimate limit of secondary stagers, will remain. This means that single stagers will be able to more easily outclass second stagers, as for most intents and purposes they can do most of what second stagers can do, but better, and are more accessible than things one must evolve for.

The current 25 gaps are:

390-415: Ledian-Furret

415-440: Furret-Persian

440-465: Persian-Forretress

465-490: Forretress-Slowbro

490-515: Slowbro-Tentacruel

515-540: Tentacruel-Snorlax

540-570: Snorlax-Silvally

Assuming Ledian gets upgraded to 400, the gaps would be:

400-425: Ledian-Dugtrio

425-450: Dugtrio-Sandslash

450-475: Sandslash-Dewgong

475-500: Dewgong-Golduck

500-525:Golduck-Cloyster

525-550: Cloyster-Volcarona

550-570: Volcarona-Silvally.

In both cases, we don't see much of a power creep. But we see a increasing stuffing in the upper and border areas. This shows the power creep is happening, but in other areas.

So, what this tells us:

• Except for a Silvally case, it is unlikely that we will see a species that reaches legendary level. However, we will likely see such a Silvally case in the next even generation or so.
• The bottom level remains 390, but this will likely change in the future to 400. However, we should expect a change from third stagers first, whose bottom level remains 385. 
• More and more archetypes will likely migrate to single stagers. This will likely leave this group with only a handful.
• Before the upper house is cleared, we will likely see more gap BSTs, like 523, 522, and so on.
• We will likely see more stat retcons, largely to match some of the existing species to other groups.

 Other notes:

• The amount of species for highest amount groups are:

1. 16=>500
2. 13=>495
3. 11=>480,
4. 8=>455
5. 7=>490
6. 6=>510,460,450, 475
7. 5=>425,485 

• This shows that upper house is getting cramped, while lower houses get cleared out. 
• For a "real" power creep to happen, to following things should occur:

1. 540-570 gap should be cleared.
2. 570-600 gap should be filled.
3. 445 and 435 points should be filled.
4. The remaining gaps are:

1. 569
2. 568
3. 565
4. 564
5. 563
6. 562
7. 561
8. 560
9. 559
10. 558
11. 557
12. 556
13. 554
14. 553
15. 552
16. 551
17. 549
18. 548
19. 547
20. 546
21. 545
22. 544
23. 543
24. 542
25. 541
26. 539
27. 538
28. 537
29. 536
30. 534
31. 533
32. 532
33. 529
34. 528
35. 527
36. 526
37. 524
38. 523
39. 522
40. 519
41. 518
42. 517
43. 516
44. 513
45. 512
46. 511
47. 509
48. 506
49. 504
50. 503
51. 502
52. 501
53. 499
54. 496
55. 493
56. 492
57. 491
58. 486
59. 484
60. 477
61. 476
62. 471
63. 469
64. 463
65. 461
66. 459
67. 458
68. 457
69. 453
70. 451
71. 449
72. 447
73. 445
74. 444
75. 443
76. 441
77. 439
78. 438
79. 437
80. 436
81. 435
82. 434
83. 433
84. 432
85. 431
86. 429
87. 428
88. 427
89. 426
90. 422
91. 421
92. 419
93. 417
94. 416
95. 414
96. 412
97. 411
98. 409
99. 408
100. 407
101. 404
102. 403
103. 402
104. 401
105. 399
106. 398
107. 397
108. 396
109. 395
110. 394
111. 393
112. 392
113. 391

Other things to note:

Because cross-generational additions are gone for good, this means that second stagers will not increase by the amount of babies or additional stages. Similarly, this means that second stagers cannot upgrade to the level of third stagers. So far, there hasn't been anything to simulate the evolution to a third stage besides Mega Evolutions and arguably Darmanitan and Cherrim's alternate forms. It might be possible that alternate forms that simulate this will be added, but it is not reasonable to expect them in the short period of time.

Similarly, though second stagers are susceptible to have side evolutions, since these side evolutions do not drastically change the outlook of power creep(besides the recent Alolan forms), it is not reasonable to expect much from there either.