A Dark Elves army appeared within the warp space.
This army, although not as massive as the Terra Expeditionary Army assembled by Robert, was nearly comparable in strength for the Dark Spirit Race, even if it wasn't utilizing their entire race's power.
In terms of numbers, it was certainly far from an all-out mobilization.
They simply couldn't achieve that.
For the Dark Spirit Race to engage in warfare within warp space, they must employ a unique technology and consume enormous energy to cloak the souls of all their members, thereby evading notice by Slaanesh.
The energy cost is immense, as the Dark Spirit Race has brought out their last reserves of wealth, with countless compressed energy crystals powering the cloaking system, yet the number of people they can conceal remains limited.
This means that although they can mobilize a considerable number of personnel overall, they can't afford any waste, let alone bring along numerous cannon fodder.
