First, high phosphorus bloom booster fertilizers are a marketing scam. Don't buy them.

Your description of yellowing leaves sounds like you are overwatering. Can you post pictures of the plant and the soil it is in. How often are you watering?

Getting the plant to bloom will most likely require more light, but you should focus on getting the plant healthy before worrying about blooms.

It's definitely not overwatered. To be honest I kind of neglected it and I watered like only once in a month and half. The soil mix is 5-1-1,a very well draining mix

Old leaves die off......that is just what happens with all plants so this could be completely natural. Read up on the details of this plant......it is very tough and very forgiving and extremely tolerant of low light and not happy in strong light. Do not move into more sun as you will risk bleaching or scorching the leaves.

And forget about flowers :-) Aspidistra is pretty shy to flower in ideal locations......I doubt you have much chance to see any flowers if grown indoors. FWIW, all houseplants bloom but not many will produce flowers when grown indoors. The conditions are just not suited to that end for the vast majority of what are typically considered "foliage plants" :-))

I know they don't like sun but in order to flower I thought i should put it in a brighter spot. But forget it, if this plant is one of those stubborn plants that never flower this plant is out of my list. One of my requirements for all my plants I grow is that, unless it's a fern they must flower.

Then I wouldn't advise growing many houseplants!! A great many will never bloom indoors or do so extremely rarely, as indoor conditions are just not very conducive to this process.

And if I may say so, you are far too new to the gardening game to be so rigid as to what is worth growing and what is not :-) I know you have an attraction to conifers.......they don't flower (or not to the extent that most folks consider 'flowering') so you are already contradicting your requirements! And many plants produce flowers that are so inconspicuous you would never notice them or the flowers are not the slightest bit attractive. Flowers are not the reason for being for gardening.....they just happen to be a delightful but very secondary bonus

Before you become too dogmatic about what will or will not work for you or rip out plants that do not meet your growth expectations or flowering requirements, try just gaining more experience. Try everything you think you may like and give it some time........2-3 years is nothing!! Give it a decade or so to make up your mind. You may find that flowers add very little to the over-all appeal.

I'm not contradicting myself because cones are an absolute must for when I choose my conifers. I am not going to grow any conifer that doesn't cone or takes decades to produce cones. It doesn't necessarily have to be flowers or conspicuous ones.. I don't care about the aesthetics. My point is, I am only going to grow a plant where it will grow to its full potential. Meaning, it will flower and fruit. And for conifers, strobili and moss, spores. For ex. I will not grow Musa basjoo because in my zone it will rarely flower and fruit, even if the foliage is beautifully attractive. I have an obsessive mind on this rule...

Well......I really don't have any response to that :-) It is your life and you are free to make whatever choices you like for whatever reasons you decide. But it's an attitude towards gardening I have never encountered before and it smacks a little of a degree of intolerance that may be hard to reconcile with gardening as a hobby and horticulture as a profession. And IMO, such a hardline dogma will greatly diminish the pleasure as well.

The rules and restrictions I make doesn't apply to my job. Its only when I grow my own plants for my own garden. I choose to use many different types of plants for the senior residents in my job as well as general landscape plants whether it's a non flowering, non Japanese, deer candy, and even some plants I personally dislike just because it is popular in the industry. This and my own personal garden is a different thing. I am still getting hands on experience with plants that aren't according to my rules and restrictions.

Sounds like the plant is under watered. Is it in a clay pot?

No in a plastic pot in a decorative container with stones on the bottom where I let the water retain and give off humidity.

I don't use a pebble tray for these, so I am not sure if it is even necessary. Every pebble tray set up I have ever heard of was a tray, not sure using the decorative pot for this purpose is the best idea. The bottom of the root zone is not an area I would think would need extra humidity.

Mine prefer plastic pots over terracotta, but I have a couple that are happy in terracotta. I do experience the odd leaf dying off though, this is likely normal. When I first got a Cast Iron Plant, it was a struggle to keep it alive. Clay pot, plastic pot, plenty of water, dry out before watering, the plant still kept dying and pushing new leaves. I eventually discovered the major problem was Mealy bugs. If your dying leaves look to have odd mottling such as green circles on the yellowing leaf, look for pests. The mealies started off looking like tiny white needles, so it was not obvious to me what was happening.

Over all I would make sure your plant is not staying wet down at the bottom of the pot. Keep the plant on the drier side with out letting it get dry. They do not want direct sun ( though small amounts of interior sun likely is fine). Everything I have read about these say not to fertilize it much. As for flowers, try giving it summer vacations outside once the weather allows. I have heard some say these will survive outside in zone 7- I am leery of that advise though. Matter of fact I remember reading here on the GWF that some one in NJ grows them outside- they die back for the winter then grow back in Spring- again I am not advising this, just saying.