This is for our new players who seem to struggle in Arena. This team will be made of farmable and free champs and will incorporate champs usable throughout the PVE content. That said, you can only expect so much out of a PVP team made up of PVE-built champs. 

Basics:

In the beginning, you'll run a speed-nuke team. You want to go first, so look for speed substats, speed sets, and speed boots. 

Order Matters: this is a turn based game, order of turns matter. You want your ATK buffer to go before Def Debuffer and Def Debuffer to go before nuker. Having your nuker as the fastest champ on the team is like putting a condom on after sex. 

Important Stats:

Accuracy - debuffs require accuracy. If your champion's accuracy is less than your opponent's resistance, debuff won't be placed. So if you see debuffs being resisted, get accuracy up. 

Crit Damage - increases the amount of damage dealt on critical hits. 

Crit Rate - increases chances of critical hit. You want it at 100% unless secified otherwise (starters require 85% on their nuke abilities)

Affinity - weak hits can't place debuffs or be critical. Weak affinity increases chances of weak hits.

Champs:

Spirithost: Aura lead (adds speed to entire team) and ATK buffer (increases ATK). She goes second to buff attack. Also very helpful as early game cleanser and Block Debuffs champion. Can be played at lvl50

Diabolist or High Khatun: TM booster (this champion goes first and boosts everybody's turn meter) they go first to propel everybody else. Both are useful for speed and control in early - mid game PVE content, as well. Worth maxing, but for arena, can be effective at 40 or 50, as long as the speed is there (Banners have speed on them, so 60 is better). 

Warmaiden: Defense Debuffer (drops enemy defense, greatly increasing damage dealt by nuker). She also hits hard, but her main priority should be accuracy to place those debuffs. Goes third to benefit from ATK boost, as well as setup for nuker. Pretty much performs the same function for PVE. Worth maxing, especially for Damage, but can be usable at 50.

Starter champ: All starter champs are great nukers. For PVE's sake, you'll have to trade ATK for speed, but you should still be able to make a fairly hard-hitting nuker. They'll probably be wearing Lifesteal, but see if you can get crit rate set on them. You'll need crit rate gloves (starters only need 85% crit.rate for their nukes), but look for crit damage in other gear. 

Notes: 

If you're going to max them, max them all the way. That means ascension, so you can use accessories.

Gear, gear, gear. Farm dungeons. Early on, climb Dragon - these same champs will be usable in Dragon, so let them earn their gear. Speed and Accuracy sets are particularly useful for early game arena, and Lifesteal is godly for PVE early on.

Stats over sets: a good pice from a crappy set is better than a crappy piece from a good set. Don't be afraid to mix and match gear where stats are needed.

Don't spread yourself thin. Build a solid team, each one of these champs performs a different function valuable for account progression. None of those NSYNC teams, with one superstar and 4 random dudes that no one remembers. 

Finally, teamwork....this game is all about synergy. Because if you think your farmer alone should be enough to get you through arena, think again. Even at mid-game, PVP champs are some of the most advanced champs in people's rosters.