Keita Ameimiya could work like a designer ?

Since GoseiWonder already started the ball rolling... :lolol

Dude, you have to contribute more than asking random questions. You're asking things that NO ONE has any more insight into than you do.

"Could Keita Amemiya work as a designer again?" Sure. Anything could happen.
"We could have objects like the infinity gems and chaos emeralds in sentai ?" Sure! Again, anything could happen.
"Should sentai could had cosmic beings like marvel ?" See above answers.
"Would be possible have a retro sentai ?" OH MY GOD, SURE! ANYTHING COULD HAPPEN!

I hate to be hard on you, as English is obviously not your first language, and you seem pretty young. But you have to post more than just one-sided questions if you don’t want the rest of us to get frustrated. Like, maybe contriubute reasons why you think each of those things would be cool, why you want them, what specifically you mean, etc... :lol

With notes of Ohranger.

And hopefully tragic real life events don't make it uncomfortable for the Japanese audience this time around. Or maybe it will and we get another goofy-ass nonsense series like Caaaaaaaaaaaaranger.

Or even better, there are no tragic events IRL and it's just naturally followed up with goofy comedic antics!

I would love a medieval knight themed sentai, but how would that motif be conducive to airplanes?

And did I miss something -- was ToQger supposed to be knight-themed at some point?

How are animals conducive to government agents with a digital arsenal? How are dinosaurs related to batteries? How are cars connected to... whatever Engine Souls are? One doesn't necessarily need to equal or imply the other.

But there is a certain romantic interpretation, particularly in the early days of aviation, of fighter pilots acting as modern day knights upon thunderous, flying metal steeds.

No, but the visors suggest it would've been perfect. Also, certain types of older trains tend to be very big and bulky. Perfect for a massive armored robot, not to mention the existence of armored trains, railway guns, etc.

But trains are boring, so better not to waste a theme on them.

Pretty sure Engine Souls are SD Cards.

Would a knight theme really work for Sentai, who are designed to be lightweight and fast?
Our Knight style characters all had more armor than usual (Black Knight, Wolzard Fire, and GoseiKnight), which isn't Sentai's usual base style.

There you go.

Platemail wasn't the only form of armor worn by knights. Chainmail would be easy enough to mimick- heck, look at the Hurricangers. Heavier armor could be an upgrade.

Also, remember, samurai are typically pictured wearing armor, and they only form on Shinkenger that was actually armored came from Power Rangers.

http://www.supersentai.com/database/...-rg-nanami.jpg
Not if you go with universal chainmail undersuit with destinguished tunics for each Senshi.

"But Gosei! That's a Ninja!"

http://pre08.deviantart.net/3631/th/...85-d5mbrr2.jpg
Real knights didn't always run around in full plate armor. In fact, that's not practical in battle because it limits mobility. Most knights wore chainmail, a thick woven tunic, a helmet and maybe some light plate armor akin to Dino Steel Mode or whatever Kyoryuger called it.