I'm thinking something along the lines of a fusion sentai. Three members (red, blue, yellow) have the power to fuse with each other into one warrior. Red+Blue=Violet, Red+Yellow=Orange, and Blue+Yellow=Green. They'll battle some force with the ability to fuse kaijin from previous series. The mecha of the series will be kinda different: each ranger gets two mecha, which can mix and match with each other into 3 Ace-Buster-like mecha, which can furthermore combine into one giant mecha. Throughout the series, they'll unlock the ability to fuse previous Sentai powers and mecha with their own powers.

The gun can have a clear light in it and when the transparent coins (colored differently) are placed, different colors will shine through

That's a pretty good idea. Also, any ideas for a 3-in-1 Silver Ranger weapon? That is the ONE place I'm having trouble.

shotgun-sword-double axe

That could work! Though, could I have a little more detail about it? I'm thinking just a steampunk shotgun that has the option of becoming a sword, but then as an ax in a secondary form, but what did YOU have in mind?

tell me if you want a more detailed sketch

Thanks! I can't tell you how much that helps! Appreciate it! That is a pretty cool idea. Wherever did you get that idea from?

Also, a more detailed sketch would be much appreciated. I can't believe you went to the trouble of sketching out for me. I was thinking you'd just describe it, but the sketch helps SO much more!

hey, no problem. only took me a minute.
and I don't know where the idea came from.

Really? Wow! If that only took you a minute, then a pic with more detail would probably look amazing!

Also, not to tie your hands, but are you gonna be adding in any steampunk elements into it? If not, it's cool. I just wanted to know.