There are 54 Pokemon that can be corrupted into the PC in Emerald (60 in FrLg).
The largest corruptions can affect 45-50 Pokemon I would say.
But that's not the number that counts, its the type of corruption that will happen to the Pokemon, as there are different reasons for turning into a Bad Egg, or not.
Usually, the pointer will corrupt a part of the Pokemon's data (Move 2, Move 4, PPs, Item, Species, Ball, EVs,..) and this corruption will turn it into a Bad Egg.
The surname can also be affected, and the Pokemon won't turn into a Bad Egg.
If the PID is corrupted, with a certain corruption (Bit 6 and not Bits 0&2), the Pokemon can turn in an Egg, and its data substructures will be swapped, as the PID manages their order.
It will work if no other data is corrupted along with the Pokemon's PID, and if some values (Move 2, PPs of Move 4, Item, Onctuosity,..) respect a certain condition.
Out of the 2*3*4 possible combinations of data substructures swap, only 10 can be obtained, but that's enough for cool corruptions.
If the TID is corrupted, (with a Bit 6 corruption), and with the same conditions as the ones needed for the PID corruption, the Pokemon will turn into an Egg.
However, its data substructures won't be swapped, since the PID manages it.
Thus, the Pokemon inside the Egg will be the Pokemon that was before, with slight changes to certain values (Move 2, Move 4, Item, Exp, Onctuosity,...), but the change on moves is the only one that can be seen, as Exp, Item, EVs, Condition are all reset when an Egg hatch.
And if we mix the last two corruptions (TID and PID), the Pokemon that was corrupted into an Egg will be corrupted again to transform into another Pokemon (the species depend on the data substructures swap), allowing us to have more control over the data of the corrupted Pokemon (Item, Exp, EVs, Condition, Moves), which allows the making of overpowered Pokemon.
This is Double Corruption, the best use of Pomeg Glitch for altering Pokemon's data.
But for a speedrun, the sole interest would be a Glitch Move that ends the battle directly, so a simple Move corruption would suffice to obtain it.
There is a lot of Instant Battle Moves, but since the Move corruption has only 4 patterns (Move = Move xor 0x4000 or 0x500 or 0x400 or 0x100), only some of them can be reached.
One of the easiest is Move 0x0537 obtained from Water Gun (0x0037).
Move Corruption 0x4000 can be done on any Pokemon, but the 3 other corruptions depend on the Pokemon's data.
Thus, the dummy that would suffer from corruption can't be any Pokemon, if it's in order to obtain a move like 0x0537. (Marill / Tentacool work well)
I don't know any Instant Victory Move with an identifiant of 0x40xx, as it would be easier in terms of Pokemon choice.
To have more sight about what's happening to a Pokemon, I made a script indicating the main data of a Pokemon (IVs, EVs, Condition, Pokerus, Item, PID, Moves, PPs, TID), with 3 modes :
Seeing data of a wild Pokemon
Seeing data of a Pokemon when its summary is opened
Seeing data of a Pokemon when its held in PC
The third mode is useful for Pomeg Glitch, as Bad Eggs frequently freeze/reset the game when their summary is seen.
Download link (it's in French, but works for US versions of Emerald)