A few first impressions.
The art? It's so incredibly well done, I absolutely love it. It's spot on gorgeous.
The facial expressions are -so- real, so correct. When Lily gives a deathly stare? You can see it in the art.
A superb job how the characters expressions change throughout the dialogue. I felt it's way up there, among the best looking (WW) games visually.
The dialogue however? I'm happy to hear you have an editor on the job. Because at this point?

The -words- are there, I can't say I came across many typos. But -so- much of the grammar, and especially syntax (the way the sentences are built up) are.. I'd say strange.
Quite often during my first 30 minute's play, I had to stop, read the text out loud, and ask myself, "What are they trying to say / relay?"
I believe I have a fair grasp of English, but this? You know the feeling when you write something, then look at it..and feel "That's not right"
"That ...looks wrong". I'm getting that feel so very often in the current build of Curse of Mantras (0.7.
Often it's the case of "I suppose.... you -could- say it that way, but it's an unusual way to express something.
Early conversation with Mantras, Lily thinks to herself" "I am not reassured, but I keep my mouth closed this time because opening it has not helped me in the slightest" This as well as so many other sentences just "feels" or "sounds" strange, when you try to read it out loud.
Next Lily "emote". "I screw up my face, bunch my fists and then pound them like a three year old on my knees"....

Here I'm struggling to understand what is happening.
Magma's first visit to Lily - "What do you know about what they want to do to me" (Magma asks "What are they planning for me, what do you know?"
That's one to many "What"s in a sentence that short.
It really is all over the place, sentences that -feel- wrong.
Lily after no longer being choked - "I massage my aching neck and cough some lungfuls of air" . (....lungfuls? It's a word for sure, but I imagine it's uncommon,
Every other slide, there's text that makes me want to pull out a red marker pen. The writing is not in a good state.
I honestly think that, this will be an issue if you were to run it by the dreaded "STEAM REVIEWS".
I'm a Norwegian with a -decent- grasp of English, but I'm far from an expert. Hopefully you let someone from the UK, who passed their English class have a look at it. It really needs to be edited. Curse of Mantras is early beta, but it really needs a lot of work, if we're talking editing.
Next? The card game is SO MUCH FUN.
It's obvious how well you know game systems / card systems. (If there's one really GOOD thing I could say about Planet Stronghold - Colonial Defense, it was the card battle system. I made a mistake of playing that game in VN mode first... I initially missed out on the good part).
:D Listening to Franka made me a believer, that card games can b e fun.
I'm not good at it, but the tutorial bits help. And I'm happy simply having won my first few battles
-> Thank you for letting me (us) play Curse of Mantras this early. Hopefully some of the input you get is useful.