Well, It's not a personal chat room. Just a surprise when something someone posted 3 years ago pops back up.
1) so learning about Arena...That's kind of tricky since there's no way to see opponents artifacts or builds. The closest thing I can tell you is that Power is almost irrelevant. Things like Resistance, C.Rate and C.DMG are large contributors to a champs power, but in the arena, speed and Accuracy are key, which play very little into Power. So likely, a team with low power is either speed and ACC heavy or just plain weak. While a team with higher power, may be slower, but have high Resist/C.rate and C.dmg. Having a tuned team is important. A team with the lead having a speed aura with a turn meter (TM) boost. High khatun, a free login champ, is really good for this early on. That pretty much qarauntees that you'll go first. An additional speed boost is helpful, but not always necessary. You'll want a champ that decreases defense (60% is prefered over 30%, and Warmaiden, a farmable rare, is great for this early-game). High Khatun (HK) will need to be super fast to get a head start on the other team, while your Decrease Defense (DEF DOWN) will need high accuracy as well as speed. For these first two, don't worry a whole lot about ATK, HP, or DEF. The third, not so fast, but with high (~100%) C.Rate and as High of C.DMG as you can get. Starter champs are typically the go too early-game. That leaves a spot for another damage dealer to finish off anyone who you didn't take out early. As you progress through the game, you'll get more champs who can fill these roles better. This is called a go-first team.