I'm on the other side of the darned room! I run to the nearest wall and sink in with geomancy (not running into it hard enough so that I would injure myself if I can't sink in), while casting blinding light spells behind me at the troll's eyes (normally they're nocturnal in most literature, so it should injure it significantly. If I fail in any of this, I rip out the iron spear with geomancy, turn it into a (thick, but tapering at the edges) serrated disk, which I begin manipulating to slash at the troll's face and *ahem* nether regions, as well as using the homing singals to draw the metal out of the troll's body. I also extend my armour spikes, hopefully increasing my protection.