The Witch is a class with the INT attribute. This makes them start at the same location as the original Witch class from PoE 1, with proximity to the Intelligence portions of the skill tree. (Top Middle)
The Witch doesn't have a signature weapon unlike other classes, but her specialty revolves around the usage of powerful dark magic to harness undead minion armies and unleash devastating bone and occult spells.
The Infernalist has a ton of passives that empower your character or army. You can summon a Loyal Hellhound to tank some of your damage, replace your Mana bar with "Infernal Flame," and more.
One passive will even allow you and your entire Minion Army to Ignite enemies with any damage type.
The Blood Mage is all about using your Life as a resource. You can stack your Life up to boost the Crit of your Spells, you can leech Life based on the damage of your Spells, and more.
If you want to be more defensive, you can take a passive that gives you extra maximum Life based on the Energy Shield of your Body Armour.
The Lich is able to obtain Eternal Life itself, harnessing the power of Energy Shield to prevent Life from changing. This Ascendancy can also invest heavily into Mana to benefit from a powerful Chaos Damage buff for herself and her allies.