There's plenty of ways to have "good magic".
For example, the "werecurse" template allows you to turn anything into anything else. For example, I'm working on coding in a booze that turns dwarves into dragons.
In addition, you could use the vampire curse template to transform a dwarf's stats any way you like. Here's the syndrome text:
[I_EFFECT:ADD_SYNDROME]
[IE_TARGET:A]
[IE_IMMEDIATE]
[IE_ARENA_NAME:Vampire]
[SYNDROME]
[SYN_CLASS:VAMPCURSE]
[CE_ADD_TAG:BLOODSUCKER:NO_AGING:STERILE:NOT_LIVING:NOEXERT:NOPAIN:NOBREATHE:NOSTUN:NONAUSEA:NO_DIZZINESS:NO_FEVERS:PARALYZEIMMUNE:NO_EAT:NO_DRINK:NO_SLEEP:NO_PHYS_ATT_GAIN:NO_PHYS_ATT_RUST:START:0]
[CE_PHYS_ATT_CHANGE:STRENGTH:200:0:AGILITY:200:0:TOUGHNESS:200:0:START:0]
[CE_MATERIAL_FORCE_MULTIPLIER:MAT_MULT:NONE:NONE:1:2]
[CE_BODY_MAT_INTERACTION:MAT_TOKEN:RESERVED_BLOOD:START:0]
[CE:INTERACTION:VAMPIRE_CURSE]
[CE:SYNDROME_TAG:SYN_INGESTED]
[CE:SYNDROME_TAG:SYN_INJECTED]
[CE_DISPLAY_TILE:TILE:165:4:0:0:START:0:CAN_BE_HIDDEN]
[CE_DISPLAY_NAME:NAME:vampire:vampires:vampiric:START:0:CAN_BE_HIDDEN]
[CE_BP_APPEARANCE_MODIFIER:START:0:BP:BY_CATEGORY:TOOTH:APPEARANCE_MODIFIER:LENGTH:150]
[CE:COUNTER_TRIGGER:DRINKING_BLOOD:1:NONE:REQUIRED]
Removing the Bloodsucker, Sterile, and NO_PHYS_ATT_GAIN would create a "curse" that you could transmit via booze that would make your dwarves into creatures that had all the advantages of a vampire, but without the need to drink blood, and they could still breed and gain stats. The "[CE_PHYS_ATT_CHANGE:STRENGTH:200:0:AGILITY:200:0:TOUGHNESS:200:0:START:0]" tag means that the creature that gains this template becomes much stronger, quicker, and tougher, which is certainly what you're looking for.