Invoke the Spirit of... erm, can't I just cast the spell?

If that is correct, there is no point of making invoke spells that casts spell with concentration duration, unless we assume that every spell spirit
has tethered magic as natural feature.

Correct. So?

So, i am just mapping what i can do with invoke and what i can't. Rules aren't that clear for me.

Ah, apologies if I seemed antagonistic. :slight_smile:

No, D: Conc spell spirits tend to be of little use.