Using Havoc's Hand with a Staff

I know the spell is designed for unarmed wizards (which is why I put this in Sparks) but I would like to be able to have a similar spell to cast upon a weapon (in this case, a staff). As it would not change any of the spell facets I don’t think I would need to reburn the spell, just reword it a little.
Havoc’s Staff (Ob3^, 4 Actions)
The sorcerer’s staff becomes a venomous blade. The merest touch wreaks havock upon his victim.
The sorcerer need only touch his victim with his staff to affect him.
Power = Will +4 (Mark). VA 1. DoF to determine IMS per touch (modified by spell success)

Note: Sorcerer must maitain contact with staff to sustain the spell

Origin: Personal. Area of Effect: Single Target
Element: Anima. Impetus: Destroy
Duration: Sustained. Resource Points: 12

Is this a resonable spell, should it be allowed?

Cool. Are the facets the same?

Would it be Earth Control if you’re supercharging a weapon?

That’s an interesting take on it. I thought that the Anima/Destroy from Havoc’s Hand refered to the Venom destroying living creatures (like a neurotoxin). The spell creates and sustains it while the wielder directs its use.
If I were to design a weapon enhancing spell from scratch I would probably need the element (lets say Fire) and the Enhance impetus (to strengthen to an otherworldly degree) Personal/Caster (or Presence/Presence depending on whose weapon (s) are being enhanced) and Sustained to keep it going along with the Earth element to allow the spell to enhance the weapon(s) in the first place.

Flaming Staff Spell (Ob 2, 2 Actions)
Origin: Personal. AoF: Single Target
Elements: Earth, Fire. Impetus: Enhance
Duration: Sustained. Resource Points: 4

When cast the mages staff ignites with a magical fire that enhances the damage done by it. It gives off light similar to that if a candle.

When used, the casters staff gains a +1 Power.
The staff must be held while spell is active or the caster suffers a may not. The spell can only be used on a staff held by the caster.

1st distillation earth/fire (Ob 1^+2^ ), (actions 6+5)÷2= Ob1.5^, 5.5 Actions
2nd distillation enhance/sustained (Ob 4^+2^), (actions 12+2) ÷2 = Ob3^ 7 Actions
3rd distillation earth/fire (Ob 1.5^, 5.5Actions)
enhance/sustained (Ob 3^, 7 Actions)
personal origin (Ob 0^, 1 Action)
single target (Ob 1^, 2 Actions)
Ob 5.5^, 15.5 Actions ÷ 2 = Ob 2.75^, 7.75 Actions
Which rounds up to Ob 3^, 8 Actions
1st compression = Ob 4^, 4 Actions
2nd compression = Ob 5^, 2 Actions
Minoris spell only works on staff in hand (4^, 2 Act)
Minoris dropping/losing staff while spell is active counts as a may not for casters sustained spells
(Ob 3^, 2Actions) spell cap (Ob 2, 2 Actions)

Note that without the spell cap extra successes could give out too much power enhancement.

Does this example sound like the right?