Astatine! (Periodic element, Atomic number 85. https://en.wikipedia.org/wiki/Astatine for more info)

Properties:

• Dark black color, but still visible against the black background (like GRAV).
• Only lives for a couple of frames, and then explodes violently into pressure, plasma, NEUT, PROT, ELEC, and PHOT.
• Can survive longer if there is not much of it.
• Kills STKM on contact.

Sorry about that. See edited post above^^

Ammonium Nitrate!

• Greyish-white powder.
• Flamable by itself.
• Oxidizer to most things; can mix with brmt, fsep, gun, and other flamable powders to make them explode better. With brmt, it will combust and get rid of the brmt.
• Can be mixed with DESL to make ANFO, a powerful explosive.
• Slightly toxic to STKM and will slowly kill him.

My suggestions:

Napalm (NPLM):

• Pale yellow liquid
• Burns at 8000 K
• Harmful to stickman.

Nitrous Oxide (N20):

• Formed when NTRG (Nitrogen) is at more than 1700K and with OXYG
• Explodes with plasma and produces a pressure of 130
• Liquified at -30C

Nitrogen (NTRG):

• Well, this isn't excatly an explosive but it's required to add N20
• Produces N20 when is at more than 1700K and with OXYG
• No flammable
• It fuses when NTRG is at 8000 K. Pressure more than 230 or
• When in contact with ISOY.
• Produces BOYL, PROT, NEUT, ELEC and heat.

Francium:

• Solid, Simmilar to RBDM but radioactive. Have a radioactive glow like URAN.
• Explodes in contact with WATR and produces ISOY (Isotope-Y)
• Explodes at 9000C into PLUT, HYGN, NEUT (thus producing a fussion chain reaction)
• Harmful to STKM, STK2 and FIGH

ANFO:

• A pink-ish powder
• Explosive with pressure, fire, and heat
• Becomes impotent in water