Chi-Yu is the perfect dark herald
After the hotfix, Chi-Yu has a base Special Attack of 135.
The ability Beads of Ruin lowers the Special Defense of everything on the field (except for Chi-Yu itself) by 25%.
This is the main part of PokƩmon's damage formula from gen 5 onwards:
Everything after the big brackets is modifiers like STAB, critical hit, weather, etc. so I'm ignoring it for the moment. Power is the move's base power, A is the relevant attacking stat, and D is the target's relevant defensive stat.
Beads of Ruin acts on D (target's Special Defense). To do the same amount of damage to the same target with a neutral ability, damage stays constant and there are no changes to other modifiers. All we care about is the A/D term: A[effective]/D = A/(0.75D), so A[effective] = 1.333...A.
Here's how actual stats are calculated for anything that isn't HP:
Basically this whole thing is A from the the previous equation. I want to know the effective base Special Attack because that's more straightforward to compare with. That means we can set this up as 1.333...(calculation done with Base=135) = (calculation done with Base(effective) which is unknown). EVs, IVs, level and nature are the same on both sides.
At this point I wrote a spreadsheet formula so I could check it with the other constants across their normal ranges - base stat is the biggest contributor but the EVs and IVs do also have an impact.
So after all that, if I haven't botched my math, its ability gives Chi-Yu a minimum effective SpA of base 182. (0IV, 0EV, any level over 3)
The highest SpA of anything that's ever existed is Mega Mewtwo Y with base 194.
Second highest is a 3-way tie at base 180 between Primal Kyogre, Mega Rayquaza, and Deoxys-Attack. But here's the thing: Deoxys-A is crazy fast and crazy strong, but has base 50 HP and 20 in both defenses so it dies if you sneeze on it. Both Rayquaza and Kyogre have to hold a specific item that does nothing other than let them go super mode.
Chi-Yu does not give up its item slot. Chi-Yu can hold an item like, oh, I don't know,
those funny glasses that prevent you from switching moves but give you +50% Special Attack
I drew this in a hurry back in 2022, and now I come back to someoneās done an entire thesis on it
