What the Knowledge Bots don't tell you:

[tself55]

Im definitely in the camp that uses the Knowledge Bots to check every difficult looking enemies stats before engaging, so that I'm fully aware of what is in store for me. However nothing can prepare you for Crawl's uncanny ability to screw with you:

DeFE rolling along nicely, already having cleared pandemonium,tartarus, and all 27 floors of a Zig, he heads into Cocytus expecting a rather easy run of firestorm and channeling. After a noneventful clearing of the Coc:7 map before charging into Antaeus's hiding corner, I learn that Crawl decided that Fire magic was too good for him, so cleverly gave him a Fire Dragon's Armour. Yay... rF- turns into rF+ and now have 700 HP worth to burn down. Takes an eventual 17 firestorms to finish him off . Clearing that zigurrat surely paid off (finding the staff of Wucad Mu on floor 25).

[Grimm]

DEFE

ftfy

[giygas]

Luckily, Antaeus is a bit of a pushover anyway with any caster; since his attacks are pretty easy to survive with rCold, you can wear him down gradually. I find Asmodeus with his hellfire most ... irritating.

[Psieye]

Provided you stay away from him, yes. Oh and that you have rElec too, he is a titan afterall.

[Galefury]

You can also just use poison arrow.

[giygas]

Provided you stay away from him, yes. Oh and that you have rElec too, he is a titan afterall.

IMO, you don't need rElec even; just keep up the Flight and DMSL spells and hover over the water, maybe summon a demonic horde to hold him back, and let Fire Storm do the rest. Though I suppose it's better to always be safer than sorry.

You can also just use poison arrow.

Or Fire Storm. Or LHS. Or Iron Shot. Or LRD. Or IMB. Or Stone Arrow.
My point is that you can kill him with almost anything; he's a pretty squishy opponent.