Currently, the fusion cycle ends at OXYG. Here's another brain-dump.
If strong gravity is introduced in the reaction, further fusion takes place which forms Molten PSCN. When even stronger gravity is introduced, the Molten PSCN fuses again into Molten IRON.
Finally, if there is extreme gravity along with max heat and max pressure, the Molten IRON becomes superheated GRVT to simulate the collapse of matter to form "Neutronium." That, or Neutronium could be added as an element, although I don't have many ideas on how it would behave.
Technically, we already have something like this. When OXYG at near max temp and pressure is introduced to a strong enough gravity field, it forms molten BMTL.
I've never observed this. :/
This might be more realistic though... if you can even consider realism with a 2D game.
Seems interesting. Although I am not sure what you mean by realistic. Like realism or realistic. Realistic would look cool, but realism would look alright.
I'm not quite sure what you mean... :/
But yes, mainly going for realism, or at least something close.
I mean how real would it look?
A relatively easy way to see this effect is to activate GPMP set to a high temperature next to the OXYG. Alternatively, detonating GBMB in close proximity to it may cause a small amount of fusion to BMTl to take place.