Big changes:
Burning Jealousy was originally a 100 BP move and still had its 100% effect chance, which implies that it had a drawback at the time that we don't know about.
Similarly,
Lash Out was a 150 BP move outright, as opposed to the 75-but-sometimes-150 BP move we know today.
From context, I assume Lash Out would have outright failed if its condition (that the user's stats were lowered) was not met, and it was buffed from the extremely binary 0-150 to a much more viable 75-150 after testing. As Burning Jealousy is something of an opposite Lash Out, I suspect it underwent a similar change: it probably outright failed if its condition wasn't met, but its power was lowered and it was revised so only the burn rate was conditional instead of the move as a whole.
Eerie Spell had the startling stats of 110 BP, 100% accuracy and 35 (56) PP.
What we got in the end was a completely different move, but more to the point, I would not take this as "an iteration of Eerie Spell" so much as "stock data from before they even started on Eerie Spell."
Incidentally, though, the move's flavor was already decided to some extent - it was already a sound-based move and bypassed subs even in this early stage!
Other nerfs:
Flip Turn was nerfed from 70 BP to 60 BP
(a good choice: this is meant to correct for its more threatening offensive type and potential for field effect abuse compared to U-turn + the scarcity of Flip Turn immunities compared to Volt Switch immunities - this is a very satisfying move that engages especially well with the value of Storm Drain in certain VGC formats, allowing it to be blocked from anywhere on the field, and I am always grateful when would-be clones are given different powers to account for fundamental differences in their types or categories);
Scorching Sands was similarly nerfed from 80 BP to 70 BP
(also a good choice: Scald is one of the strongest moves, and Ground is an insane attacking type that synergizes with its effect for reasons similar to Water, but Scorching Sands is widely distributed among Fire-types as well and Ground/Fire is pretty frightening coverage);
Expanding Force was nerfed from 85 BP to 80 BP;
Skitter Smack was nerfed from 80 BP to 70 BP;
Poltergeist was nerfed from 120 BP and 100% accuracy to 110 BP and 90% accuracy;
Scale Shot was nerfed from 30 BP to 25 BP
(this one interests me! it did already hit 2-5 times at this point in development, so it would have been the strongest such move by power in addition to its effect; a bit of a longshot, but I wonder if it used to have only the Defense-lowering drawback, and the associated Speed boost might have come after it was nerfed? there's no way to determine this from what we can see in Legends, unfortunately - either way, I really like where this move ended up, so no complaints!);
and
Misty Explosion was nerfed from 120 BP to 100 BP
(this is also interesting! I have always thought the move was strangely designed and blatantly underpowered compared to the other terrain moves, especially Expanding Force; this tells us they actually tried it at a higher power and didn't like how it played for some reason, so I'm curious about what that process was like but will no longer assume it was a mistake!)
Other buffs:
Obviously
Triple Axel's power was straight doubled;
Corrosive Gas was buffed from a 20 BP special move to a non-damaging status move
(it traded minor chip of a weak attacking type for the ability to remove items from Poison-immune targets, since status moves in general don't obey type-based immunities, which is definitely an improvement! but here's something neat: it tells us that if Corrosive Gas were a damaging utility move, the power they would have chosen was 20, the same as pre-buff Knock!);
and
Glacial Lance was buffed from a 120 BP move
(the same as Astral Barrage) to a 130 BP move
(10 more than Astral Barrage, which was intentionally not changed - the point was making the physical attacker that has to deal with Intimidate and burns and stuff hit harder up front! this is very standard fare and good design, even if I think Astral Barrage's BP is way too high for its type and maybe it would have been better to create the desired dissonance by nerfing that one).
