ToME: the Tales of Maj'Eyal

Beware! It is a large purple 'X' (and yes, it does move over impassable terrain) almost 700 HP at level 20, and it multiplies.
I ran into it at level 3 of Daikara. I had to retreat back up the stairs to Daikara level 2, with my lev 27 Yeek Archmage. They hit pretty hard.
Any ideas on how to kill it / them? Or should I just try to teleport past them, and pray I find the stairs down before they find me, and multiply even more?

If you kill them you unlock geomancy. The method I was using - isolate them from the other critters by retreat. Concentrate on single, kill, go previous level, restore, return, repeat. No special tactic, the same as u do with other wall-walkers. They don't multiply, the number is fixed, but death of one heal others.

Once you kill all but one of the fragments, the last one gets a big power-up. Killing that one unlocks Geomancy for archmages.

It doesn't actually multiply, there are simply several to begin with (they are fragments after all). You usually see one first, and then others start moving into view so I guess it could look like multiplying.

Thanks for the clarification! I managed to kill the buggers. If it weren't for your advice, I probably would have telepassed it and missed the unlock.