Casimir Liber
Adventurer
I have no problem with it going to CR 8 if it makes narrative sense. 6 hyenas is better.
Rephrasing is fine
Spectral Pack. The gnoll beast shaman is surrounded by a ghostly pack of hyenas. Normally intangible (insubstantial?) and harmless, the shaman can summon spectral hyenas from this pack to serve it on the Material Plane. The number of spectral hyenas the shaman can summon cannot exceed six. The beast shaman can send any spectral hyena it summons back to the spirit realm as a free action.
Rephrasing is fine
Spectral Pack. The gnoll beast shaman is surrounded by a ghostly pack of hyenas. Normally intangible (insubstantial?) and harmless, the shaman can summon spectral hyenas from this pack to serve it on the Material Plane. The number of spectral hyenas the shaman can summon cannot exceed six. The beast shaman can send any spectral hyena it summons back to the spirit realm as a free action.