@Steampunkette I've had a question since I first read Paranormal Power (which I love BTW) a few weeks ago: Why did you decide to make the various Mind Strike options bonus actions rather than Actions? They seem pretty cantrip-adjacent in terms of power and combat cantrips are typically Actions.
Not a criticism, I haven't seen the Esper in play so I don't have in game experience of its power level and comparison to other classes. I've just been super curious as someone who has a (very) amateurish interest in game design.
And as others have said, a truly impressive piece of work. I wish you tons of success in this and future endeavors (which I will certainly back, hint hint!).
It's because they're meant to combine with the powers to create a flexible dual-wielding style of ranged combat.
All of the powers have a sort of 'Baseline' function that is usable at any time. Essentially a cantrip that only grows in power by 1 point each time you gain an Esper Level if it deals damage. That means that while a Sorcerer is throwing 4d10s at level 20 (4-40 damage per attack) an Esper at level 20 using their baseline Telekinesis power, for example, can deal 1d8+20 (21-28, much higher guaranteed damage, but not as much damage total)
Which is where the Mind Strike comes in. As an additional 2d6+5 (Maximum normal intelligence bonus) that's another 7-17 damage. Maximum of 45 damage, but a minimum of 28 and it requires both your action -and- bonus action. Add in the "Double Jeopardy" of having to make two attack rolls, or giving the target multiple saves, or a save and an attack roll... you'll still do a nice baseline of damage but rarely -excel- at it.
Of course, if you use your action to actually augment your power with extra damage, you can essentially 'Cast a Spell' and follow it up with a Mind-Strike on the same turn. Essentially limitless "Bonus action Cantrip" that deals about 1/5th the damage of a regular cantrip at max level, but early game is actually fairly strong.
The offset, of course, are the powers that an Esper gets access to. While Telekinesis for example deals 1d8+1 at level 1, you have to use both of your psi dice as augments to make it deal as much damage in a single cast as a 1st level spell typically deals. That power use also won't be AoE, like Thunderwave or Burning Hands, but single-target. Though you might retain one or both your psi dice after casting it (essentially not expending the 'spell slot') you're still kinda limited overall. (If you did want to do two targets you could deal 2d8+1 to each target, or three targets for 1d8+1 each)
Great consistent all day damage with a growing floor... but your top-end is never going to match a Sorcerer or Wizard for strict damage dealing, unless you mind-control one and blow all their good spells on themself and their minions.
And, of course, on turns when you -have- to spend your action doing something else (Like dashing, dodging, or doing environmental interactions) you still have your Mind-Strike as a little "Hey, Buddy. Take some damage!" function.
I'm really happy that you're enjoying Paranormal Power, and I thank you for your well wishes! <3