[Spoilers] Orphan Help.

[Morgalodia]

How the hell do you beat this bastard?

I have:

Lightning - Com
Snow - Sen
Hope - Med

My two most used paradigms are:

Lightning - Med Snow - Sen Hope - Med
Lightning - Com Snow - Rav Hope - Rav

I usually switch between those and one where Hope is a synergist to buff up the party but I usually end up dying when his frickin' Progenitor attack or whatever kills me in one hit.
I can take Merciless Judgement just fine and heal up really quick with Med-Med-Sen after that.

What's a quicker way of dealing him damage as he casts Doom on you at some point as well.

[Harlequin]

How the hell do you beat this bastard?

I have:

Lightning - Com
Snow - Sen
Hope - Med

My two most used paradigms are:

Lightning - Med Snow - Sen Hope - Med
Lightning - Com Snow - Rav Hope - Rav

I usually switch between those and one where Hope is a synergist to buff up the party but I usually end up dying when his frickin' Progenitor attack or whatever kills me in one hit.
I can take Merciless Judgement just fine and heal up really quick with Med-Med-Sen after that.

What's a quicker way of dealing him damage as he casts Doom on you at some point as well.

That's the same party I used

Party: Lightning, Snow, Hope

Paradigms:

Rav, Com, Rav
Com, Com, Rav
Rav, Sen, Rav
Com, Sen, Rav
Med, Sen, Syn
Med, Sen, Med

First off, you're generally ill advised to go into the battle without three Cherub Crowns equiped on your party leader. Orphan deals death to a random character (Sen doesn't work as a decoy), ending the battle instantly. Not that you'll be immune to his death you understand, just that you'll have a higher chance of surviving than not.

I advise equiping Hope with rainbow anklets(?) - the ones that stop him from being struck down with that annoying malady that doesn't let you cast magic. Orphan has two forms, light and dark, and when he switches to dark his attacks inflict a crippling range of buffs which can quickly reduce your role in the battle to spectator.

When the battle starts he hits you with his ultimate move. This won't kill you, but will certainly leave you vulnerable to the unrelenting abuse that follows. Start with Protection and Hope will cast haste on as many characters as possible before you're struck by the crippler. Switch immediately to Combat Clinic then back to Protection once the critical status of your party has been remedied. Once done, hit him with either Solidarity then Mystic Tower or go straight into Mystic Tower.

The damage his claw does should be (by and large) negligable, allowing you to pile on the chain gauge with Relentless Assault, with the odd safety switch to Solidarity. When staggered, choose between Relentless Assault to drive up the damage multiplier or Aggression to have two Commandos beat down on him.

When his chain gauge depletes into it's last quarter it's imperitive you switch to Combat Clinic, seeing as he hits you with that overpowered move that's more than likely going to leave your party once again on the brink.

It's not as simple as repeat however. After the first stagger is over he'll switch to his dark side and begin to bestow status ailments on your team. This is why it's vital you have Hope and Lightning spamming Esunas and Cura/Curajas throughout this form. Switch to Protection when he dispels haste, the speed is vital to survival. Staggering him in this mode should stop him from attacking you, and after the stagger period is over he begins to use his ultimate move and death randomly.

Concentration and patience is vital to winning this battle.

Good Luck

Relatively minor spoiler -

Spoiler!

There is a second form that should be a breeze after the initial battle. This form is impervious to damage but is quite easy to stagger and once staggered takes a sizable amount of damage.

It should only withstand two or three staggers. It's damage isn't much of a worry so it's pratically a token boss.