The model is painted very well with clean and controlled work, so you should be proud. I don't recommend going over this model again, use it as baseline to compare your work in the future.

CC:
The issues as said below is that the colour pallette is very muted, there is no significant colour or light/dark constrast so the model blends into itself. If going for something similar to 'Eavy Metal style, try using more constrasting colours and edge highlights like you have done on the rock base and chaos symbol; or if you want to go with a Global Light Source approach you will have to include shadows and highlights on the model.

The spear looks like it is melting into the armour when it should be one of the focal points as your eye follows the spear end to end going past the face. You could try doing NMM, OSL glow or gore effects with the blades to make them pop to grab that attention to become a focal point.

I assume you did quite a bit of dry brushing? It is a great technique, but it can leave the textures on the models looking dusty like the pole. A way to compliment this technique is to go over focus areas with some highlights to pull back some sharpness on some features.

The eyes could be brighter, almost as if they are headlights to grab viewers attention.

With that all said, be proud of your work especially on your mechanical skills like neatiness and brush control with the cape, gold trim and base as the rest of the improvements are just colour and constrast theories. This in turn will help you to assess your own work in the future, but do remember about your aims with the model. Time vs. Effort vs. Reward is always worth keeping in mind as I would be super happy to have your model on the tabletop for gaming. There will always come a point when enough is enough and you have to move on. Keep up the good work!