More skills...
Game needs more skills, and better explanation about how nodes effect damage scale, what effects what. Sure, you may simply say "explore yourself" but sometimes bugs or lag causes some stuff to not work properly. Fixing bugs, optimizing games are different subject. But, players have to know if their calculations and choices were wrong, or their non-viable builds are result of bugs.

A few skill ideas to help:
Giant Arrow: Fire a single giant arrow. Arrow deals physical damage, and knocks enemies back. Has a long range but low attack speed. Also explodes on impact to deal area damage. Player can charge the skill to increase the size of the arrow to a certain limit.
Skill damage type can be changed with skill adjustments. Arrow may chain between enemies with a certain selection, arrow may pull enemies to player, arrow may not knockback enemies at all, increasing attack speed etc is an option as well.

Wall spells, Spells that changes certain terrain like, adding a platform to reach to distance, etc...
It can add a different playstyle. Something like an Architecture. You build stuff to kill mobs. Build kill-boxes for mobs... A new idea. Using unique skills such as this can give Wolcen an edge and uniqueness against other ARPG's.
A few examples:
Stone Wall:
Instantly creates a wall of stone on the targeted location. Activate the skill to choose the place you want to build the wall. (Insert a few control options) to rotate the wall. And activate the skill again to place it. Wall will damage enemies that are standing in its center and knock them back to closest free space.
Certain boss attacks may destroy the wall and can damage you.
Walls will stay in a certain duration. THey can connect to other walls to reset their duration.
Skill has a long cooldown or has high willpower cost that may increase each time player puts another wall. Duration may be set to a fixed upper limit.
Different skill selections may turn it to flame wall that deals DoT, Frost wall, lightning wall, or poison wall, bleed wall,
Maybe moving wall of thorns. Like a moving chainsaw or a gigantic rock that crushes enemies.

Platform:
Can be build on the stone wall. Grants increased range to projectiles. Grants better vision. Turrets and similar skills can be placed here.
Using platforms will make you visible to more enemies and they can attack you as well. You may need to defend the ladders of platform to prevent enemies to come and kill you.

Tower:
Build a tower that shoots (Insert spell, projectile or similar stuff)
Skill changes can change the projectile type, can make the tower pour lava or boiling oil to enemies to make them receive increased fire damage, etc...

New skill type: Illusion

Causing fear, or frenzy, or making enemies exit combat state, making them turn against each other, etc...

New skill type: Utility.
Doesn't deal damage but creates various useful effects.
Example: Antimagic Shield
-Creates a dome made from magical energy. All kinds of spells will automatically cancelled including players. Attacks will work fine but skills/abilities that requires staff or catalyst won't work. Affects bosses and mobs as well.

Toggle skills:
Blizzard: Creates a blizzard around the player. Skill consumes x amount of willpower. Enemies will receive cold damage over time, and slowed. Enemies hit by cold spells has chance to freeze.
Skill can be changed to a duration spell,

Firestorm or lightning storm skills are also a possibility.

You can go simple as well...
Adding effects on next melee/ranged attacks or a buff skill that grants x amount of elemental, occult or material damage to next attack or attack skill. Making a melee default attack character viable could be interesting since dash can be used a lot more times with correct nodes. It could be a nice option i think.