Ok, I think this will work regardless of whether this is a thoughtform or an actual entity, as long as you remember to use clear visualization of your desired outcomes and put your energy into it.
Just saying words does nothing by itself, entity or no.
Legitimacy? (Legibility means it’s readable.) Not 100% reliable, trust your gut, then take a risk and you live and earn.
If you make sure you’re clean and your protections are in place, and you are equipped to deal with an issue if it arises (like, know how to banish and cleanse) then you’ should be ok.
based upon you saying it can be used for luck, prosperity and success.
I think it sounds like this spirit could be Duke Berith(28 in Ars Goetia)
sometimes spirits use new and or different names and say that they are someone else if the practitioner maybe aren’t ready for the truth of who they are, Duke Berith is also considered too be a trickster spirit.