A Quick Guide to Colosseum

So, Colosseum is the hardest dungeon out there in NA (looking at you, 3P). This is basically "The Idiot's Guide to Clearing Colosseum". Pretty short, but it's simple if you look at it. 

First off, lead. What lead do I use? You want both damage and survivability. Some examples are:
- RaDra (2.25/144/2.25, extra damage with tpa's)
- Aizen (144x with one dark cross, 4x rcv, and subs/leads have high hp)
- Meri (kills almost all floors with one row, 6.25x rcv, leads/subs have high hp)
- Kenshin/Ilmina (two crosses kills most floors, damage reduction when matching fire and light). 
You got your examples. Dath isn't that decent since you need to do 49x damage to heal, and that makes stalling difficult. 

Next, skills. Whether it be a sub or inherit, you'll need:
- Gravity. Depending on the team, you'll use it on Orpharion (definently, he has a 50% resolve and does a kill shot when below 50%), MZeus/MHera (probably, depends if you can go below 81% resolve and not trigger anything big), and Achtros/Deighk (only 30% gravity works, and you can just use a delay or poison since you'll have to charge up gravity again). 
- Delay. If you choose not to gravity Achtros/Deighk, the best option is a delay. That way you can stall out their preemptive shield and absorb. You won't use it anywhere else, so make sure the base form has a useful skill also (ex Isis, shield and bind clear useful depending on team). 
- Poison. Depending on your team, you use this to kill pys, and if you don't bring a delay for Achtros/Deighk, a poison works too. 
- Gemstone. A 2/3x burst works too, but only if your team can still do ~50 million damage with it. 
- Shield. 3 turn Indra is best for the no HP multiplier leads, 5 turn Susano is more beneficial if you're already running a lead with an HP multiplier / damage reduction lead. 

So now you've got your team and inherits, but how do I do the dungeon? 
Skills to pop: Delay/Poison/Gravity on Achtros/Deighk. Gemstone on Sevenzard (depending on team, can wait for him to switch to a more favorable color). Gravity and gemstone on MZeus/MHera (use gemstone turn to chip Seraphis below resolve). Gravity and gemstone on Orpharion. 
Floors you can stall on: 
- Floor 2. The flower dragons make infinite hearts for you, so you can basically stall there for all your skills. 
- Floor 12, depending on your spawn. Wood and light knight is the best to stall on (just remember to match the mortal poisons when you get 3 on the light knight). Water you can only stall a few turns, and the fire/dark knight isn't that great to stall on. 
- Floor 16, if you get Mion. She guarantees at least 3 hearts whenever she does a board change, so that makes stalling easier. 
- Seraphis. The only problem however is that his skillset is very random, so you have to get pray he doesn't use Core Burst (around 55k)
- Orpharion. He's pretty easy since he only hits for 21k each turn when above 50%, and he does something random (bind, orb lock, awoken bind, etc). Just remember on the first turn to damage him, because he does a skill delay when at full hp. 


So that's about it. Don't forget that Colosseum spawns are RNG, so make sure you can deal with all spawns, and the rest is up to player skill and knowing the dungeon (spawns, skill sets, etc). If you're trying to clear for the first time, coop always helps. If you have any questions, you can message me @Gnar on Discord. Hopefully this guide helps!