Atem spell resisted seems to resist entire damage

[Fermouth]

Giant Fortress, Animal Pen
You notice 5 giant spiked collars here.
Also here: giant war dog, giant war dog, giant war dog, giant war dog, giant
war dog, giant war dog, giant war dog, giant war dog, giant war dog, giant war
dog.
Obvious exits: north, west, southwest
[HP=xxx/MA=xxx]:atem
*Combat Engaged*
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 236 damage!
You attempt to cast acid tempest on giant war dog, but the spell is resisted!
The giant war dog viciously bites you for 6 damage!
The giant war dog hits you, but the swing glances off!
The giant war dog hits you, but the swing glances off!
The giant war dog snaps at you with its teeth!
The giant war dog hits you, but the swing glances off!
The giant war dog snaps at you with its teeth!
The giant war dog hits you, but the swing glances off!
The giant war dog hits you, but the swing glances off!
The giant war dog snaps at you with its teeth!
The giant war dog hits you, but the swing glances off!
The giant war dog hits you, but the swing glances off!
The giant war dog lunges at you!
The giant war dog snaps at you with its teeth!
The giant war dog mauls you for 1 damage!
The giant war dog hits you, but the swing glances off!
The giant war dog snaps at you with its teeth!
The giant war dog hits you, but the swing glances off!
The giant war dog mauls you for 4 damage!
The giant war dog mauls you for 2 damage!
The giant war dog hits you, but the swing glances off!
The giant war dog snaps at you with its teeth!
The giant war dog snaps at you with its teeth!
The giant war dog mauls you for 3 damage!
The giant war dog mauls you for 2 damage!
The giant war dog snaps at you with its teeth!
The giant war dog hits you, but the swing glances off!
The giant war dog hits you, but the swing glances off!
The giant war dog hits you, but the swing glances off!
The giant war dog hits you, but the swing glances off!
The giant war dog snaps at you with its teeth!
[HP=xxx/MA=xxx]:atem
*Combat Off*
*Combat Engaged*
[HP=xxx/MA=xxx]:atem
*Combat Off*
*Combat Engaged*
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 102 damage!
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 102 damage!
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 102 damage!
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 102 damage!
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 102 damage!
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
You attempt to cast drenched in acid on giant war dog, but the spell is resisted
!
The giant war dog mauls you for 3 damage!
The giant war dog snaps at you with its teeth!
The giant war dog hits you, but the swing glances off!
[HP=xxx/MA=xxx]:
Giant Fortress, Animal Pen
You notice 5 giant spiked collars here.
Also here: giant war dog.
Obvious exits: north, west, southwest
[HP=xxx/MA=xxx]:atem giant war dog
*Combat Off*
*Combat Engaged*
You summon a powerful tempest into the room!
Your foes are drenched in acid as the wind batters them for 214 damage!
The giant war dog lets out a yelp and dies!
You gain 1800 experience.
*Combat Off*
[HP=xxx/MA=xxx]:

Giant war dogs have 300 hitpoints and 55 magic resistance and 50/1 ac.
It appears that on one round one of the war dogs resisted the spell entirely thus making me have to cast atem again, thus wasting my mana :(

Plz fix this, kthx.