Custom Minecraft PvP Plugin Development

I'm seeking an experienced Minecraft plugin developer to create a custom progression and ability system tailored for PvP.

Key Requirements:
- Kill-based progression: Players earn 'cores' from PvP kills to unlock various abilities.
- Abilities to include:
- Combat enhancements (e.g., increased damage, speed)
- Special moves (e.g., teleportation, fireballs)
- Defensive skills (e.g., shields, damage reduction)

Ideal Skills and Experience:
- Proficient in Java and Minecraft plugin development
- Strong understanding of PvP mechanics and balance
- Experience with custom game modes and progression systems
- Ability to test and debug effectively

Please provide examples of previous work, particularly in PvP-related plugins.

Examples
Strength SMP Plugin
Other Power plugins