Meng Meng here to answer all your questions~! ^o^
Let's get started, then...
What is power and how do I raise it?Edit
It's tied to the strength of your warriors. Its main purpose is for player-versus-player battles. You raise it by increasing your warriors' HP, attack, EXP, and strengthening their armor. You can also increase your lord skills using cultivate pills from Encounter. Make sure to level up your warriors and take good care of them. :)
How do I get gold warriors?Edit
One thing's for sure, Meng Meng won't get you one for free. You gotta work hard. There are actually five ways of getting them.
1. Get 30 Tokens to buy one directly from Saga Mode. You get tokens by buying them through discount (20 gold apiece) or earn them by spending 500 credits. Sometimes you can get them through 1st Blood or Meng Meng's wish if you're lucky.
2. If you're really lucky, you can synthesize one through hero synthesis. This is based more on luck.
3. If you're REALLY lucky, you can get one through your level nine Tavern.
4. You can win one through iBox/Meng Meng's Treasure Box. Your possibilities are Golden Diao Chan, Xiao Qiao, Lv Bu, Sun Ce, Xu Chu, Guo Jia, and Wei Yan.
5. Buy every warrior in each class allows you to get one gold warrior for free. For example, if you buy all of the archers in saga mode, you have a chance to get one free Gold archer for free! It will take some time because you can't buy all of the characters in Saga mode until you reach level 49, but it is worth it.
Also, by getting a perfect completion of the second chapter of the campaigns you can either get Cao Pei or golden Zhen Ji for free! All is not lost, my lord. :D
And one more thing, raising your hero's aptitude won't change their color so they won't ever suddenly become gold...