In Arkham Horror, players may use the spell Red Sign of Shudde M'ell to lower a monster's toughness by 1 (to a minimum of 1) until the end of this combat. In the event that an investigator has multiple copies of that spell (let's say 5) against a monster with a high enough toughness (almost like the Dunwich Horror), can that investigator cast all those spells over multiple combat rounds to effectively reduce that monster's toughness to the minimum of 1? Or reduce all of its abilities to absolutely nothing?
I believe that both effects of that spell are stateful and affects the monster's traits waaaay after the spells are cast and subsequently released, but I just want to make sure.
The Arkham Horror rules state that:
A spell or weapon that gives you a bonus (even one that says it lasts until the end of combat) only continues to give you the bonus while you devote the required number of hands to it.
Normally, for spells like Withering, which gives a combat bonus of three (3), that means the bonus goes away the next combat round when you've released the spell. However, the Red Sign of Shudde M'ell does not provide any combat bonus whatsoever. Just like the item "Shotgun", which confers a raw 6 ability distinct from its combat bonus, the spell has an effect outside of its normal combat bonus of zero (0).
So after successfully casting and exhausting two of those spell cards, the player can release both hands and then successfully cast another two copies of that particular spell to both reduce the toughness of a monster by four blood drops and remove four of either "Overwhelming X", "Endless", "Physical Immunity", "Physical Resistance", "Magical Resistance", and "Ambush" at the end of two combat rounds.
To recap: Can you release the hands used for a successfully cast Red Sign of Shudde M'ell after a combat round without forfeiting the spell's benefits in later combat rounds?
OT: Terse recapitulation is hard.