My gf clearer Tombs solo yesterday with the SF/sliver build (we started same time but I lagged out in 3rd room).
I tried again today and completed it. Only thing you have to watch out for is not pulling too many grasps, and when you have them on you...make sure you let sliver kill the grasps first. For the worm pops, just note where they pop and be ready for them coming. Make sure you have a fresh SF up, then when they pop just stand still by them and they wont slide back into the earth. Sliver kills them fairly quickly if you have enough enemy attacking you.
Another good hint - especially for level 3 and 4 - is to allow the casters to follow you to the worms (once you've killed those annoying grasps). That way you can take the worms down quicker. Also, don't kill everything and then try to kill the Darkness guys...keep some caster on you and hitting you, it'll make taking them down much quicker
The only skills I found myself using were Glyph of Swiftness, DP, SF, Glyph of Lesser Energy, Intensity and Sliver...as I don't have the Vanguard skill.
You don't really get much, but it's fun to do at least once
