If you have another reliable way to proc Crown, then use that and keep Imp for the guardians. The advantage of Imp is that it has no cooldown, so it can proc very often if you have a quick attack (Which 5 guardians definitely do)
Maul: Archon, Level 100 (GD 1.2.1.3) - Grim Dawn Build Calculator
Full Pyran: Archon, Level 100 (GD 1.2.1.3) - Grim Dawn Build Calculator (this one doesn,t have the healing rain proc, but it’s really not necessary: the devotion bonuses should be enough