I like this idea, a lot, and I love that a relationship could be established between a weapon and player, but I've read through and I can't seem to find where you address the issue of limiting yourself through this weapon. The ability to toggle it should be severely nerfed in comparison to other weapons, as the "relationship" should not only give pros, but cons. You should have to commit yourself to your weapon more. Like a (dare I say it) cooldown for the ability to toggle it. I say this because the ability to mesh with you should take some time. Establishing a link, I mean. It should also take time to break said link.
Like Commylooses from Kid Icarus? http://kidicarus.wikia.com/wiki/Commyloose Except they latch onto your arm and shoot bullets instead of bombs?
I always considered it to be kind of like a (depending on type) would resemble a cephalopod (kind of like a octopus), it would wrap its tentacles/tendrils onto your right/left arm and you could only have 1 on your person (in inventory) at a time, if you found another kar'nak (name of species) it would have to be transported to your ship where it will stay in your science lab, In order to use it you would need to take off the one you were using by going to the lab and then having the other symbiotic weapon melded on. I really enjoy your idea of making it so it cannot be quick switched, give it a 5 minute time for it to complete melding before you can use it would be good for making it so it is not overpowered. Prehaps give it the ability to take some of your health to regenerate its ammo if it reaches zero before it can recharge by itself. When you have one melded onto your arm you can still use another weapon as it would be more attatched to your forearm so your hand is still free to use when it is not "activated" or in use. The more you use the kar'nak and get kills with it and feeding it rare DNA from certain aliens and creatures it will trust you more and grow stronger, upgrading its damage,ammo recharge rate or enhancing its abilities, E.G the spiker could have the ability to make each shot have a chance to penetrate the target and hit whatever is behind it, if fed enough DNA. A high trust with the creature which is gained from use and kills will reduce the time it takes to meld with you when switching to other symbiote weapons, recharges ammo faster and Health points used to regerate ammo is reduced. Im also thinking that the Kar'naks should have randomly generated names, so it can be seen as a creature more then just a weapon.
Kinda reminds me of the sword Nightmare uses from Soul Caliber... Interesting idea though! I can see it happening.
Kind of like that, but not a weapon seperated from your body, it would most likely be a bone-like blade extending from a creature on your forearm.
I'm loving this idea, reminds me of the Yuuzhan Vong from Star Wars. One way of adding this without making it "limiting" would be to perhaps have a race (Maybe those Flower people?) that uses only organic 'technology'. They can grow/meld with different creatures, forming a symbiotic relationship with their equipment (weapons, armor, ships, ect. ect.). I'm sure this idea has been tossed up a lot, just thought I'd give my piece on it.
