Clearing Vaults:5 entrance with level 3 and 4 spells

Those spells combo so well! These plus mephitic cloud and cloud immunity was one of the most fun runs I've ever had!

that reminds me of the time I got a Demonspawn with Burning Blood and the Firestarter mace. just KABOOOM all around the place. good times.

[deleted]

OTR + ignite poison is excellent in a lot of areas, surprisingly. You can clear a screen's worth of stuff pretty fast in other areas of vaults, spider, shoals, orc, elf, depths, and even a good chunk of enemies in Zot. Mephitic is really good as a stabbing/non-rPois unique buster too. Without heavy spell training you can get ~25% chance/turn a vault warden or deep elf annihilator is in the clouds to confuse for example, and since it costs 3 mana you can carpet the approach in it, quickly outperforming even high levels of the confuse spell for non-resistant monsters.

Since lots of monsters resist poison you need other stuff to support (same for stuff with 20+ HD, where mephitic will rarely actually work), but none of the above requires a large amount of XP for most species. Bigger issue is simply getting the spells. Mephitic is pretty common, showing up in 3 non-random books, including two starter books. Ignite poison is in two, OTR only in young poisoner's.