I suspect lawyers disagree with me, but until you get any profits from releasing your work (you will distribute it for free, right?), and honestly refer to source and credit the copyrights owner company - it should be fine.
Again, lawyers probably disagree.
On the other hand - your work is free advertisement for their product, so it would be extremely stupid to sue you.
Would it be stupid? Absolutely. Will they do it? Maybe. It really depends. Take Blizzard as an example in regards to legacy servers (though to be fair they got ad money in that case so there
were damages).
In general, corporations are the epitome of greed and more often than not they're corrupt at certain levels. Even if their employees are not, the incentive of the entire organization as a whole is solely to "make more money, invest, and expand" and everything (including stonewalling anything that they even
think could harm their brand/IP) revolves around that concept and that concept alone. It's how the entire corporate system is constructed pretty much from the ground up due to extremely fierce competition both from without and from within. Skim costs as much as possible while only making the smallest amount of people angry (even then there are actual metrics to "how mad" a person can get before they do anything - such as quit or lose productivity or form a union - and the idea is to ride the line as
close as possible) while increasing profits as much as possible as well. Obviously not everyone who works for a corporation actively thinks along these lines, but the very rules/policies of the organization are set up to incentivize this and people often "job zone" and put blinders on in an attempt to do their job well and try and not think of the consequences as much as possible.
Even their "charity" - while often quite real - is only a scheme to literally buy the public's goodwill in order to get more people to recognize their brand or buy their product because "they're the good guys" - which is why they typically advertise their "charity of the month" like crazy... (it's literally how charity is often pitched in office meetings too - the actual human decency factor comes second to what can be sold to the shareholders to increase the value of their investment through better brand recognition). It's a sad fact of life, unfortunately.
I read up on a lot of the Supreme Court cases regarding copyright infringement from IP, etc, and I can tell you that corporations have gotten even
legitimate work to be considered "copyright infringement" if the corporation is big enough and they can make a case for it. They oftentimes can also bend the existing law. (Seriously, the actual content creator was sued for publishing something similar after he left the company for example. Or take Disney preventing Mickey Mouse from becoming part of the common domain even when the law states it should- because it's still the most popular children IP by a huge margin over its competitors.)
This is because, for the most part, IP and copyright infringement is very much a legal gray area that is open to interpretation and circumstance case by case. Thing is, if the company really cares they will have better lawyers and probably win. Not always, but most of the time. Another part of the problem is that technological IP is fairly new in the grand scheme of things.
That being said, most companies don't sue for the sole reason of public outlook (again, see charity) but EA has shown in the past that it doesn't care much about public opinion so be careful about how you reference things. Just food for thought. I don't want to discourage you, but I want you to be informed of the overall risks. I seriously, and I mean seriously, doubt they would bother with an "inspired by" mod but definitely don't use any actual assets now that you have their official response. I'd even avoid the name Kane. Maybe actually just use Cain? They don't have a trademark on that obviously as it's a biblical name for crying out loud, but anything to avoid their overall attention would probably be for the best.