Light type is just NO! Why is that its super effective against Dark something everyone is excited about? Theres only ONE bulky dark type, Tyranitar, and he's 4x weak to fighting already, and steel, and bug, and water, and grass. Seriously, light types popularity is just no. Its already covered ensemble by fire, steel, and for a small amount, bug. Unless you want to revamp a bunch of moves and maybe change like Ampharos and Togekisses typing, light is a terrible typing. And some other I have to shut down.
Wood: FOR GODS SAKES, ITS GRASS! Never metnion this, ever
Lava: Same as wood, but its fire
Ninja: This is dark and fighting together, little bit of steel... sort of secretly love this but it wouldnt work
Magic: Its ghost and psychic together pretty much, has small potential
Skull: Ghost
Wind: I know that its the only element missing, but Flying covers it
Digital: Its ok, sort of a decent idea, but doesnt have enough to really work with
Virus: Its pretty much poison, same if anyone said Radiation and I missed it
Plastic: Sort of like tougher normal typing, doesnt have any merit really
Cosmic: The only really decent one so far, although Im opposed to new types in general, Clefable and a few toher pokes could benefit, but it would be hard because a few Pokemon have 2 typings, another one wouldnt really work, like Metagross and Palkia could be cosmic typing.
So, theres my opinion on THAT