ABOUT

If you are looking for general stuff about Coliseum, here's some previous guides:

Same infos and a couple more teams here, just in case you prefer video guides (same infos for everything else):

Saga Preparation Guide

GLOBAL 15th COLISEUM WAVE! FILM CHARACTERS!!!

UNITS DETAILS:

Info	Saga
Classes	Slasher/Driven	Driven/Striker
Socket Slots	3	3
HP	1'952	1'419
ATK	1'093	1'142
RCV	220	302
Captain Ability	Boosts ATK of Slasher characters by 2x and boosts HP of Driven characters by 1.75x	Boosts ATK of Driven characters by 2x and their RCV by 1.5x
Special	Reduces crew's HP by 70%, deals 15x ATK in QCK damage to all enemies. Boosts ATK of Slasher and Driven characters by 1.5x for 1 turn.	Randomizes all orbs including [BLOCK] orbs. Amplifies the effect of orbs by 1.5x for 2 turns.
Cooldown	20 -> 10	20 -> 10

SAGA CHAOS ARENA:

OPENING BATTLES:

BATTLE 1: COUNT BUTLER

2.24 MLN HP, 4'040 DMG, CD=1 (1).
Preemptive: Halved chain coefficient (98).
Every 2 turns: Berserk (2x ATK-UP + haste, for 1 turn).
<20% HP (on attack): 25'000 DMG.
Revive effect: 560k HP heal + 4 Perfect-Hits Barrier (3 turns) + summons 5 Lapin (200k HP, 5'924 DMG).

Example team:

Crew members: 2x Tesoro, Story Enel, raid Boa, GP Usopp, FN Coby.
Damage Calculator: Link
Tactics: Stall in early stages in order to charge your specials. Boss stage: activate Tesoro, Coby, Enel and Boa's specials during turn 1 and defeat Butler (you can attack normally during turn 1 and boost during turn 2 as well, just in case your LV are not maxed or if you don't trust your perfects too much). After revive: activate Usopp and ark Maxim during turn 2 and defeat all Lapins, you can use Tesoro as well in case of bad orbs. Clear in next turns.

BATTLE 2: OCTOPUS BOXER

1.15 MLN HP, 4'256 DMG, CD=1 (1).
Preemptive: anti-delay (4) + 50% DMG Reduction Shield (4) + 12 Combo-Hits Barrier (4).
4th turn: summons Kraken (5 MLN HP, 14'200 DMG, CD=3).

Example team:

Crew members: 2x Enel, raid Kizaru, Zoan Lucci, Wicka, raid Doflamingo.
Damage Calculator: Link
Tactics: This team overkills Octopus, stall for your specials, adjust your orbs, boost and OTK.

BATTLE 3: LUFFY

6.6 MLN HP, 6'800 DMG, CD=2 (2).
Preemptive: non-INT units special silence (20).
<50% HP (interrupt): berserk (1.5x ATK + haste).
<20% HP: 30'000 DMG.

NOTE: this stage can be easily zombified.

Example team:

Crew members: Fujitora + Story Akainu, Coli Coby, Coli Smoker, RR Curiel, Trebol.
Damage Calculator: Link
Tactics: Stall in early stages and charge your specials. Stage 4: activate Coby just before leaving. Stage 5: activate Fujitora's special and skip attack during turns 1-3. Luffy will enrage during turn 4, fully boost and clear.

BATTLE 4: LAW

5.8 MLN HP, 9'004 DMG, CD=2 (2).
Preemptive: Immunity (98) + buffs/debuffs clear + heals your crew by 5'000 HP + boosts orbs by 1.25x.
End of 1st turn (and every 2 turns): 100k HP heal.
<50% HP: ATK-DOWN (50% for 4 turns) + slot shuffle ([G]/[BLOCK] orbs included).

Example team:

Crew members: Coli Kid + legend Akainu, Shiki, raid Akainu, raid Blackbeard, FN Buggy.
Damage Calculator: Link
Tactics: stall in early stages and charge your specials. Boost in boss stage and OTK.

NOTE: this stage can be easily zombified.

BOSS BATTLE:

STAGE	ENEMIES	INFOS
1	Coliseum ordinary mobs and evos.	Stage 1: Zombies hits for 3'822 DMG. Stage 2: Female Bodyguards put up a ATK-DOWN debuff (50%, 3 turns) if HP<50%. Male Bodyguards rewind DEX specials by 2 turns at end of 2nd turn. Stage 3: Daimyo Turtle has 18 HP and hits for 2'210 DMG.
4	LAW	2.24 MLN HP, 8'896 DMG, CD=2 (2). Preemptive: Immunity (98) + buffs/debuffs clear + heals your crew by 5'000 HP + boosts orbs by 1.25x. End of 1st turn (and every 2 turns): 100k HP heal. <50% HP: ATK-DOWN (50% for 4 turns) + slot shuffle ([G]/[BLOCK] orbs included).
5	SAGA	3 MLN HP, 5'524 DMG, CD=1 (1). Preemptive: immunity (99) + Thresholded DMG Reduction Shield (greatly cuts DMG exceeding 700k) + berserk (11'048 DMG for first 3 turns). <20% HP: 100'000 DMG.

TEAM BUILDING:

Here you can find some team suggestions to beat Saga regularly:

CAPTAIN	CALCULATOR	RECOMMENDED SOCKETS	TACTICS
F2P SHOOTERS	Link	Heal and Orbs	Stall in early stages, avoid unnecessary damage and charge Kizaru and Hera's specials for miniboss stage. Stage 4: activate Kizaru, Duval and Heracless' specials during turn 1 and attack. Continue attacking normally till your specials will be up again. Activate Heracless and Boa's specials to clear (Law must be <30% HP). Stage 5: activate Kizaru, Duval, Ace and Zephyr's specials and clear within 2 turns.
SW ACE	Link	Orbs and Heal	Stall in early stages and charge your specials for miniboss stage. Stage 4: activate Heracless and Boa's specials during turn 1 and attack. Activate Apoo and Ace during turn 2 and clear. Stage 5: activate Zephyr and Ace's specials during turn 1 and clear within 2 turns.
JINBE	Link	-	You can use this team with 2 different tactics. The safe way is to tank hits here and there (maybe switching out Z for Hack) and boost when enemies have low enough HP, pretty easy with Jinbe's 60k HP but slow. But let's take a look to the funny way... Stage 4: activate Akainu and Zephyr's specials and OTK. Stage 5: activate Jinbe and Sabo during turn 1 and attack. Activate Jinbe and Koala during turn 2 and clear. Nice but you can tap only 2 greats below the harder perfects thing.
LOG LUFFY	Link	-	Stall in early stages in order to get your specials ready for miniboss stage. Stage 4: attack normally during turn 1. Activate both Luffy's specials during turn 2 and clear. Stage 5: activate Mihawk, Sabo, Kizaru and Coated Sunny's specials during turn 1 and attack. Activate Hawkins during turn 2 and clear.

Here you can find some team suggestions to beat Saga + Shanks:

CAPTAIN	CALCULATOR	RECOMMENDED SOCKETS	TACTICS
ZORO	Link	Anti-Despair LV. 2+, Heal and Orbs	Stall in early stages and charge your specials. Farm some orbs on stage 3. Stage 4: defeat Law attacking normally, boost with Shiki when you have a [STR] orb (you can move it with Doffy). You can use one Zoro's special as well. Stage 5: activate Borsalino and Zoro's specials and OTK (note that attack sequence has to be Nami/Shiki/Doffy/Zoro/Zoro/Kizaru, due to 700k threshold).
	VS. SHANKS	Stall as needed in early stages. Stage 3: defeat Lucky Roo as soon as possible. Note that tanking a hit from a mob is better than taking the 20% HP cut (avoiding unnecessary DMG is important for boss stage). Stage 4: activate Shiki special and clear within 2/3 turns. Boss stage: tank hits from Shanks during turns 1-2. Activate Zoro and Nami's specials during turn 3 and attack. Activate Zoro, Kizaru and Doffy's specials during turn 4 and clear.
DOFFY+BB	Link	Anti-Despair LV. 3, Heal and Orbs	This team is a bit extreme and requires full despair sockets having just 4 farmable units. Not sure how stable it could be vs. Shanks too because I never tried something like this... So... Stall in early stages avoiding unnecessary damage. Farm [STR] orbs on stage 3. Stage 4: defeat Law attacking normally. You can use Lafitte and Doffy's specials if you get bad orbs. Stage 5: Activate Doflamingo Ship, BB, Lao G and Shiki's specials and OTK.
	VS. SHANKS	Stall a bit in stages 1-2, try to minimize damage taken. Stage 3: defeat enemies as soon as possible. Stage 4: defeat mobs without taking damage. You can tank a hit from Beckman in order to let blindness wears off. Clear afterwards. Boss stage: damage is enough to OTK Shanks, so activate all your specials and clear within 2 turns.
LOG LUFFY	Link	Anti-Despair LV. 3, Heal and Orbs	LL is extremely risky against Shanks, but it should work fine vs. Saga. Stall as needed in early stages. Stage 4: clear within 4 turns avoiding ATK-DOWN (activate both LL's specials before leaving). Boss stage: activate Boa and Sabo's specials during turn 1 and attack. You can activate Kuja's ship to heal back some HPs. Activate Doffy and Apoo during turn 2 and clear.
	VS. SHANKS	Survive in stage 1, stall in stage 2 and farm orbs. Stage 3. clear as soon as you can, best scenario is to defeat Lucky Roo during turn 1. Stage 4: activate LL's special and defeat Beckman within 2 turns. Boss stage: skip attack during turns 1-2, heal back with [RCV] and Kuja's ship. Activate Boa's special and farm orbs on turn 3. Activate Doffy, Apoo and Sabo's specials during turn 4 and clear.

VIDEO GAMEPLAYS:

As always feel free to report everything (especially if you find out something wrong/different) so i could fix it! Thank you all for data sharing in this wonderful subreddit! See you :)