Its not really the summons that I am concerned about, its status effects.
I don't think you have any problem with any status effects. I seriously doubt it.
Regardless, I don't think they can claim ownership of mythology...
No they can't, anymore than JKRowling's Harry Potter can claim ownership of dragons and basilisks.
But my point had nothing to do with whether Square Enix owned them, and everything to do with whether your game world is too similar to Square Enix's game world. It's a different question that doesn't have to do with the ownership of the individual pieces, but how similar your games are after you assemble the pieces.
If I make a sandcastle and you make a sandcastle, I can't claim ownership of the sand. But I can claim ownership of how I used the sand in the big picture of my complete castle. If your sandcastle looks too similar to mine, then there's a problem.
But just because they are both castles, and just because they are both made out of sand, doesn't make it similar enough to be a problem.
Regardless, I don't think they can claim ownership of mythology so I think I could probably be safe using odin or ifrit.
Why then do you think they can claim ownership of 'petrify' and 'silence' status affects? Many games use those also, and Square Enix didn't invent petrification or muting of magic.
Why are you worried about something you shouldn't be worried about (status affect names used by hundreds of games), and why aren't you worried about something you maybe should be (the exact specific names of items almost exclusively used by Final Fantasy)?
And again, I'm talking in generalities, I'm not saying you must rename 'Phoenix down' or lawyers will kick down your door. I'm just saying, taking your entire game, and holding it against Square Enix's property, how much in total does your game borrow? If it's a very tiny amount, you're probably safe. If it's a noticeable amount, you maybe might not be.
If I made a first person shooter and used Phoenix Downs, there wouldn't be a problem. If I made an RPG and used Phoenix Down, there wouldn't be a problem. If I made an RPG and used thirty or forty different Square Enix items and creatures, and used them in similar ways and settings to Square Enix's usages, then there might be a problem, maybe - it depends on how far you decide to take the similarities.
Nobody knows 100% what you can or can't do. It's not true or false question. It's a matter of "how much" will you borrow? Borrowing some of it is fine. Borrowing too much is risky. Borrowing all of it is suicide. How much is "too much"? A lawyer can tell you when you might be getting close, but he can never tell you perfectly.
Just work on your game, and when it gets closer to completion, the similarities will become apparent. And they will be easy to fix, even late in development. So don't sweat it too much.
Little of triple triad remains in my idea, other than face values and grid based play. And I somehow suspect I may be the only person that thinks its a good concept
Triple Triad was popular. As I mentioned, popular enough that Square Enix re-released it just two weeks ago (Feb 23, 2015) in their Final Fantasy 14 MMO.
It's good that little of (the original) Triple Triad remains. You probably don't have any problem then. I probably was assuming much worse, since there is a lack of details given,
its an idea I've been thinking of for a while now and I've only just started exploring ideas for it last week.
Keep exploring it! Definitely worth sticking with it.
at this rate I'll probably just lose hope for it and put it aside!
Me: "Thousands of of mythological characters are available. If you're worried about legal issues, just avoid those very few specific ones." -> You: "Well maybe I won't use ANY mythology then!"
Me: "If you are worried about item names, change up the item names. There's plenty of good names to use, just avoid those few specific ones." -> You: "Well! I'll probably just quit making the game all together!"
I'm not a lawyer, and while I do programming and design, I'm no amazingly fantastic programmer or designer (I'm fairly decent, but not yet a master at either). But I am a human who has many flaws, and if you want some advice from a flawed human, here it is:
First of all, when someone is giving you intelligent criticism and advice that you asked for, don't get discouraged. Use the constructive criticism to make informed decisions and improve yourself and your work. Informed decisions can include, "this doesn't apply to me" (if you actually are reasonably certain it doesn't apply). Because only you know yourself, and only you know your own thoughts and plans for your game. I'm only seeing the barest glimpses conveyed through a few bare snippets of text.
Second of all, talking about legal issues is normally hope-draining for everyone! So don't let it sink your ship. It's normally hopeless, because legal details NEVER benefit, they are purely defensive to prevent loss. And since they are loss-preventing, ofcourse we have to talk about the loss. The law never creates value. This is expected, and it's good to prepare yourself emotionally for that whenever you go into any kind of legal question.
Third, try not to make mountains out of anthills. I'm saying 'HERE is how you identify a problem'. 'IF there is a problem, it can be fixed VERY easily, using SMALL changes, without ruining anything'. The proper reaction is, "Okay, thanks, I'll keep that in mind if it looks like it is becoming a problem.", not, "Oh the hopelessness! This ruins everything! I might as well just give up now!". (Okay, I'm exaggerating your response somewhat. )
Fourth of all, don't let life get in the way of creativity. If you are genuinely creative, stick with it, be passionate about it. You aren't familiar with copyright law, so ofcourse you're going to be confused and discouraged. Plan ahead for the discouragement. Alot of game development has discouragement in it - tracking bugs in your code, dealing with annoyed customers, dealing with bad reviews, dealing with the business side of things, not making progress as fast as you hoped, and so on. Don't let the frustrating parts prevent you from experiencing the enjoying parts: seeing your code function properly, watching others enjoy your game, reading good reviews, learning about how things work, seeing your creation come to life over time, and more.
Basically, don't let yourself prevent yourself from making the game you want to make.
I really don't think you have much of a problem, I'm just pointing out what areas I think may become a problem, how to identify them, and how to fix them. Nothing worth fretting over.
So, once more, good luck on your game, I look forward to someday playing it.