I could not reproduce this. as the previous poster mentioned he probably fought against some Pokemon with Inner Focus, Oblivious, Scrappy or Own Tempo.
Step 1 : Give yourself an Blissey
Code: Select allBlissey (F)
Ability: Natural Cure
Level: 100
Shiny: NO
Happiness: 0
BASHFUL Nature
IVs: 4 HP / 23 Atk / 21 Def / 18 SpA / 5 SpD / 2 Spe
Poke Ball: poke_ball
Growth: Ordinary
- Morning Sun
- Sing
- Light Screen
- Last Resort
Step 2: Give yourself an Landorus or Arcanine with Intimidate ( i tested both )
Step 3: /pokespawn Raticate lvl:60 move1:tackle move2:tackle move3:tackle move4:tackle atkev:252
Step 4: Enter Battle with your Blissey
Step 5: Raticate uses tackle and deals ~ 100 dmg
Step 6: Switch in the Intimidate Pokemon
Step 7: Switch back to Blissey
Step 8: Raticate uses tackle and deals ~ 50 dmg
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Working as intended. Not a Bug.