The levels from the opponent are based up on your level, my pandaffodil opponent was an nature at level 13.
1. Frostfang - Rock rhino
2. Pyro pony - Frostfang
3. Rock rhino - Bamboon (nature)
4. Pandaffodil - Pyro pony
5. Skyger - Rampage (fire)
6. Rainguin - Pandaffodil
7. Fairy ferret - Pyro pony
8. Frostfang - Bamboon (nature)
9. Skyger - Rampage (fire)
10. Firefox - Frostfang
11. Plantlers - Pandaffodil
12. Turtisle - Skyger
13. Rock rhino - Bamboon (earth)
14. Pyro pony - Frostfang
15. Chromadile - Fire glider (electric)
16. Pandaffodil - Rampage (fire)
17. Skyger - Rampage (fire)
18. Armordillo - Glacial griffin (water)
19. Firefox - Frostfang
20. Dream bat - Pandaffodil
21. Rock rhino - Bamboon (nature)
22. Volcamel - Glacial griffin (water)
23. Fairy ferret - Pyro pony
24. Plantlers - Pandaffodil
25. Ember bear - Frostfang
26. Skyger - Rampage (fire)
27. Jackalope - Pyro pony
28. Planther - Pyro pony
29. Aquatter - Pandaffodil
30. Chameneon - Pandaffodil
31. Pandaffodil - Pyro pony
32. Racmoon - Fairy ferret (nature)
33. Bamboon - Rampage (fire)
34. Solar simian - Pyro pony
35. Peamoth - Pyro pony
36. Rampage - Pyro pony
37. Iciclaw - Pandaffodil
38. Rockodile - Pandaffodil
39. Volcamel Pandaffodil
40. Spruce moose - Frostfang
41. Jackalope - Pyro pony
42. Dream bat - Fairy ferret (nature)
43. Rampage - Forstfang
44. Solar simian - Pyro pony
45. Gargolem - Pandaffodil
46. Pyro pony - Frostfang
47. Chameneon - Rock rhino
48. Peamoth - Pyro pony
49. Iciclaw - Pandaffodil
50. Cosmic phoenix - Chameneon (water)
51. Rainguin - Pandaffodil
52. Bamboon - Pyro pony
53. Ancient sloth - Pandaffodil
54. Glacial griffin - Pandaffodil
55. Sea drake - Rock rhino (2 critical hits)
56. Rock rhino - Bamboon (nature)
57. Aquatter - Lightning leopard
58. Magmacore - Ancient sloth (rock)
59. Ocean Owl - Pandaffodil
60. Aurora pegasus - Fire glider (fire)
61. Ember bear - Fire glider (fire)
62. Spruce moose - fire glider (fire)
63. Grassquatch - Ancient sloth (nature)
64. Vinotaur - Frostfang
65. Onyx Ox - Pyro pony
66. Turtisle - Lightning leopard
67. Dream bat - Fairy ferret (nature)
68. Gargolem - Fairy ferret (nature)
69. Magmacore - Rock rhino
70. Emerald Dragon - Pyro pony
71. Chromadile - Fairy ferret (nature, fire, nature, nature - all weaks)
72. Hydro yak - Pyro pony
73. Cosmic pheonix - Pyro pony
74. Glacial griffin - Pandaffodil
75. Crystal unicorn - Pyro pony
76. Rockodile - Pandaffodil
77. Aurora pegasus - Pyro pony
78. Onyx ox - Pyro pony
79. Emerald dragon - Pyro pony
80. Twilight troll - Pyro pony
And when we have a 1 or a 2 as a notification in the menu - battle, that's mean we have our energy recharded.