Grand Hero Battle - Legion

Basically shift your mages around so you can eliminate all enemies within striking distance of you on each turn so on the enemies turn you can get hit. Use Ninian to dance only in order to shift and second hit as needed. Should take 5 turns.

Desperation Nino, Basic Linde and Tharja. Any dancer should work in Ninian place.

Works for lunatic. Nowi only needs to be 4 stars and bane/boon dosent meatter for any of the characters. Eldigan needs reposition Julia needs a boost from either fury, triangle adept, or L & D. Use Julia to kill Legion on right. Repsoition Azura with Eldigan once Julia gets her second move thats needed to kill Legion. Then defend the right corner and use nowi to saftly bait the red mage and if needed bait left Legion with Eldigan. Then kill the two units (bow and Legion) that will come down. Kill the bow first and if your Julia cant in one move either then kill bow with Eldigan and baot legion or give Julia a second turn with Azura and use reposition if needed. Eldigan can be replaced by a Xander. Azura can be replaced by any dancer. Camus can replace Nowi. These are for f2p and require few orbs. Julia is the only required unit but can be replaced by Sanaki or Tharja.

For infernal
Hone-elise
Fortify-reinhardt
Goad-camus
Ward-xander
-Xander and camus have vantage and fury.
-they have damaging specials bonfire and dragon fang.
-Healer should have heavenly light, everyone gets extremely hurt, plus they have savage blow.
Started off by giving camus all buffs and putting him at top left to bait red mage and archer, xander was 2 spaces under to ward.
Basically just kept healing and buffing the knights and using the tiles as much as possible, reinhardt was only there for the buffs and snipes.

I had 4 star neutral Xander and olivia with 5 star reinhardt (+att - spd) and cecilia (+Res - Def). Simply rush your reinhardt and cecilia into range of the mages and have the others wait just outside of range, then proceed to wipe out all but the Legions. Fill in the gaps with your reds and the rest is pie. Just make sure you have a ruby sword or tri advantage on Olivia.

I used this team to beat Infernal. For Lunatic I used Ryoma instead of Olivia, but that was only to give Tharja hone speed buff without axebreaker. He didn't help much otherwise.

For Infernal:
Tharja has axebreaker and needs hone attack buff from Olivia to ORKO Legion barring the one with Aegis. Olivia was 4-star, lv.34, but it didn't matter. Keep her out of range of everything, especially red mage with swordbreaker. After all Legions are dead, have Tharja kill red mage or else axebreaker will be compromised. My Ninian had TA2, should be safe taking damage from red or blue mages (she had 37 speed though, +spd nature plus one merge).

My Soren had heavy investment. Gronnraven+, triangle adept 2, B tomebreaker 2, growing wind. Both Soren and Tharja had Draw Back for extra movement. This was necessary to move each other, themselves, or dancers out of line of fire. Have Soren kill blue mages and brave bow user (archer must be attacked, he is guaranteed to kill one of your characters on enemy's turn!).

For the most part keep Olivia with Tharja and Ninian with Soren, but sometimes may need to swap, or give someone 3 turns.

That's it. Go for right side first (kill Legion with Tharja, Olivia gets her out of line of fire of blue mage, Tharja drags her back, Soren moves in range of blue mage.). After that, move towards bottom right, then finish in the middle.

Tharja had neutral nature plus attack seal, Soren +att, -hp, one merge giving hp, spd.