I would tune it as follows:
- 210pts - Dreadlord, cold one, heavy armour, sea dragon cloak, dawnstone, great weapon
- 245pts - Supreme Sorceress, Level 3, Cold One, Dark Magic
- 205pts - 20 Dreadspears, Banner, Musician, Gleaming Pennant
- 120pts - 10 Darkshards
- 100pts - 5 Dark Riders, Repeater Crossbows
- 150pts - 5 Cold One Knights
You could consider putting the Sorceress on foot, to free some points for upgrades here and there, like a musician for the cold one knights. Alternatively, you could drop the gleaming pennant and the cold one on the sorceress to upgrade her to level 4 or give her a fun toy to play with

If you're open to any list then there are countless of options to go to. Which one will give you the most fun depends heavily on the situation:
- What models do you have available?
- What models do you like?
- Do you prefer a list focused on a theme or a play style?
- Is it made for competition, or local gaming groups?
- Do you want the same units at larger point sizes?
- How many models are you willing to paint? Infantry armies will have considerably more models

It's easy to swap to an entirely different army on paper, but in all fairness, what you have right now looks like a balanced start and it resembles a list I played with quite often. It works and it's fun. If you already have the models, then I'd go with this list and try it out.
If you want to keep all options open, then let's start with where you want to go and we can discuss units within that context.
Good luck!
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