I tried playing Solipsist many times. I was always scared of the reduced HP, and I always died in the early game from lack of Psi.
Until it dawned on me that there is no need to spam all the skills. The starting ability with 2 cooldowns gets you through the first 20 levels, allowing you to focus on other things.

Many pleasant discoveries awaited me.
1. Huge area damage.
2. Good survivability, which you don't expect from a class with cut HP. The main thing is not to run into a one-shot. Lol, even being lvl 40 I accidentally summoned GOD (lvl 130+) in the "endless dungeon", and left only because I took off 30% of his HP and I got tired of those 15 minutes.
3. Saves. I was able to achieve 100% conversion of mental saves to all other saves. And raise saves to 100. I didn't need to use cleansing because I resisted everything.
4. Speed. 180% global speed. Wow-wow.
5. Sleep is fun. It helps you get 1-2 turns of impunity, during which you can prepare the battlefield.
6. Well, and just a narrative. You bend the world with your will so much that you simply ignore all the obstacles it gives you. But in a dream there are no obstacles, right?