Swap puncture for slash if using the hold mechanic of your 4. This is because the tap mechanic deals puncture damage when her 4 explodes, and this damage is increased via puncture mods and not by the other ips mods (its increased by base damage mods and elementals tho). The hold mechanic of her 1 over her 4 makes it explode dealing slash damage, thats why you swap the mods

[Fragor Prime] is the ideal choice for her stat stick due to it having extra innate combo. Other weapons do work and rivens with +combo count are good aswell