It seems that directional spells are a bit buggy in arena.
Here are some examples from the fight of Asper versus Iwku, with Asper using cone of cold.
Iwku was riding a stallion.
Casting directional spells at Iwku ends up in : You power up a cone of cold attack.
No damage is done.
Casting directionals at the stallion is a bit buggy. Before combat with the stallion, casting directional spells at it will give a 0.00x) Your cone of cold ...... (a zero multiplier)
At this point, hitting the stallion with directionals results in Asper unable to move. Typing n s e w will give the same result as a return, ie, your prompt is shown, but Asper can't move out. Only way to get out of it is to 'flee'. Think this is the same bug Erwin experienced with Fizban in the last KOTM, Erwin got out with 'retreat'.
After typing 'kill all' and getting involved in combat with Iwku and the stallion, I can fire off cone of colds at the stallion.
However, strangely, the directional spells I fire show the damage on my prompt, like it was a regular physical combat. (Normally, damage done by firing directional spells on mobs don't show up on the prompt) Furthermore, I saw that the damage dealt was constant, 100 damage per cone of cold.
After the stallion died, I tried to use directional spells again, but still came up with a "You power up a cone of cold attack.", and it doesn't do any damage at all.
Yup, think that's about it