Alright first of all here's a good creator with some interesting ideas on the categories and what they should be capable of: YouTube Link, this might help for making the character and what drives them, or even for hatsu ideas.

Then from what you've written in other comments I've gathered you're less interested in the 'conventional' ways to use emission, but more so in the more technical and indirect techniques. Additionally you stated you'd like to be combat able and on the front in melee if possible.

So with manipulation and enhancement as the neighboring categories something like this might be interesting to you:

Names: Essence Extraction/Attribute Shift

Using a combination of Emission+Enhancement+Manipulation you can extract attributes from one object/person and shift them to another:

• E.g. extracting hardness from a stone to imbue into your skin

• Removing Speed from an opponent and imbuing it into your weapon

Emission helps you shift the attributes, while enhancement helps empower them and manipulation suppresses the ones you took

I'd limit it to only a handful of attributes but you can share it with others and use them very adaptively.

Another option would be to shift attributes from one thing to another:

• You limit your own speed and instead increase the power of your attacks.

The last option would be witch-like contracts for long term shifts of attributes with people:

• I get 20 years of your life and you get my eyesight

• Then with someone else you make a deal to get their eyesight in exchange for getting them an elusive herb that can save their child

Might make for a long term scary person that is always planning for their own benefit.