(Another) New WaM Spell

[Rhezha]

I know, I know... there's a whole lot of proposed new WaM spells on here, but this is a spell I thought simply should exist in the Belariath universe, and it makes most sense to be a WaM spell. Hope it's intriguing for people! As always, I would love to hear feedback and thoughts on my ideas!

Edit Version: 1

Anywhere Spell

True Strength (name needs work)
Level required: 14
Class Required: Warrior-Mage
Casting Method: N/A
Defending Method: N/A
Description: The warrior mage knows that versatility is key for survival and every situation calls for a different approach. While a mix of magic and blade is often effective, sometimes sheer brawn is required to overcome an obstacle. By use of this spell, the warrior-mage is able to temporarily channel a portion of their magical ability into an increase in physical strength. It is not to be done lightly however, as the spell cannot be canceled early and may only be cast once per combat. However, the effects can be devastating for an unsuspecting foe expecting a spell over a heavy blow.
Note: Though an “anywhere” spell, this spell must be recast after the start of combat, regardless of whether it was active beforehand.

:MECHANICS: Upon casting, the warrior-mage temporarily sacrifices 10% of their intelligence score for every time the warrior-mage class has been selected. For every intelligence point lost, the caster receives a temporary boost to their strength score for the same amount. The spell costs 1 stamina point plus 1 for each slot invested and demands 1 extra stamina every round it is active. The spell lasts 1 round for every 2 slots invested after the first slot. The spell will not end until it expires, combat begins, or the caster is rendered unconscious. The spell may only be cast once per combat.
Example: Warrior-mage X3 Kathleen casts 7 slots of the spell. She has a base Int score of 65 and a base Str score of 52. She loses 30% of her int = 19.5 -> 20 points and gains this as strength score, leaving her at 72 strength and 45 intelligence for 4 rounds after spending 8 stamina in the first round and 1 stamina each successive round that it's active.