I don't actually have a character sheet for the Dwarf Grenade Thrower, but it seems pretty straightforward to me. Metatype B, Attributes A, Magic C, Skills E, Resources D. He uses literally 0 weapons but grenades, so gotta have that maxed out in your skills. He has the following Adept Powers: Improved Reflexes (what rank is unsure, but you probably want 3), Mystic Armor (no idea what rank), Improved Skill (Grenades), Combat Sense (again, no idea what rank), and possibly Enhanced Accuracy (Grenades). Assuming you get Exceptional Attribute - Magic, you can get Improved Reflexes 2, Combat Sense 2, Mystic Armor 2, Improved Skill (Grenades) 4, Enhanced Accuracy (Grenades) 2. Exchange 2 levels of Improved Skill, or 1 level of Improved Skill and both levels of Enhanced Accuracy if you want Improved Reflexes 3. Well, you honestly can drop whatever you want, like you can drop Combat Sense to 1 and Mystic Armor to 1, or Combat Sense to 1 and 1 rank of Improved Skill; you get the point, if you want Improved Reflexes 3, it's not hard.
Gear seems to just be standard Armor Vest plus a hell of a lot of Grenades. You probably want a Fake SIN in there too, but that isn't covered in the story. Edit: I should clarify that he says 20 Grenades is packing light. He normally goes in with 36. He doesn't seem to use Smoke Grenades, so I'm assuming either 12 Flashbangs, 12 High-explosive, and 12 Fragmentation Grenades per run, or possibly 8 Flashbangs, 14 High-Explosive, and 14 Fragmentation Grenades. Like he says in the story, they sure as hell aren't quiet, but they are effective. It will cost you 18,000 nuyen to get 30 of each type of Grenade, which should hold you for a couple of runs at least, after which you need to resupply. As for other gear, that's up to you.
For Attributes, you probably want to max out Agility (or put it at one below, 5) and get a good Body, Willpower, and Strength. Finally, a good Intuiton and Reaction. Probably want something like this: Body 5, Agility 5, Reaction 4, Strength 7, Charisma 3, Intuition 5, Logic 3, Willpower 5. Swap out points from Strength to Body if you want a bulkier guy, since he doesn't use Strength that much. Just remember Strength determines range from Grenades.
