UnitMysticCost: 2ATK: 1 HP: 1
Opposing heroes can't level up.
PurplePresent Tech II

Card-Specific Rulings
This prevents opposing heroes from gaining levels by any means. That includes killing another player's hero, and effects like Training Grounds. — Sirlin
Blackhand Resurrector's ability puts a hero into play a level 1, rather than max level, if an opponent has Chronofixer. — Sirlin
Untargetable Rulings
Something that's untargetable still CAN be attacked. It can even be affected by some spells and abilities, but NOT spells or abilities that use the [target] symbol. — Sirlin