The Mother

Strategy
The Mother is a fairly difficult fight. A strategy that works fairly well, is to find all the crystals (requires a rogue to get all of them) and place them in the stone circles through the halls on the way to the fight. This will give you up to three special 1 use abilities that will help greatly with the fight. You can also side with the Architect to gain another aoe ability that can help, but this is at your discretion.

During the fight, The Mother uses her tentacles (similar to the Broodmother from Origins) and calls forth Childer Grubs, creating what can quickly become panic, if the situation is not controlled, to an otherwise easy fight. One way to control them is to have a mage, or two, use spells such as Blizzard and Tempest over the area where most of the enemies accumulate, or to have a high damage character attempt to thin them off a bit while the others bring down The Mother as fast as possible. Do not be afraid to use the special 1 use abilities, as they can turn the tide if things get out of hand.