A Vilkalizer™ brand mod (accept no substitutes!) for Baldur's Gate II: Throne of Bhaal
This is a simple mod that turns mages' and clerics' high level abilities into innate abilities, thus freeing up the ninth- or seventh-level spell slots for actual ninth- or seventh-level spells. They now work similarly to other classes' HLAs, meaning each time you pick an ability, you get one use per day out of it. The HLA tables have been edited to allow the player to pick abilities multiple times.
Unlike other classes, casters' HLAs will still show up in their spellcasting menu, not their innate abilities menu. This was initially unintended, but makes sense seeing as they are, in fact, high level spells.
Unpack HLAbilities.zip to the folder where you have Baldur's Gate II installed. Unless you specified another location on install, that defaults to C:\Program Files\Black Isle\BGII - SoA
Run setup-highlevelABILITIES.exe and follow the instructions.
To uninstall the mod, run the setup program again.
"But what does it actually do?"