i said full concept... and also oda didn't wanna reveal to much about haki back then cuz it would just confuse us, haki was explained after the war.Bullshit. We had:
1. Mantra, or Observation Haki
2. Sentomaru using Haki against Luffy
3. Garp hurting Luffy with punches at Water 7
4. Haki usage during Marineford, like Jozu hitting Aokiji and Crocodile, Whitebeard striking Akainu, the three Admirals blocking WB's quake with Armament, and the fact that it was actually called Haki at multiple points.
5. Rayleigh giving the explanation for what Haki was PRE-SKIP
6. Kuja Pirates on Amazon Lily using Haki-infused arrows
7. Luffy's burst of Haki in Impel Down
8. Shanks using Haoshoku from the very first chapter
Oda clearly had the idea of Haki in mind pre-timeskip, the only new thing we got so far from Haki was Buso: Koka