Terrified...

[RiisWolf]

PLDs are not a great choice to start with.
They have the weakest threat and not cause of damage, the threat modifier are literally lower than the WAR and DRK, both which whom are stronger than the Paladin.
Your defenses are as effective as everyone elses. Seriously, the RNG is weak, the long CDs are gone for too long for the 20%s they block.
They have no self sustainability, which is a big no, no considering who weak they are at defense.
You're ability to deal AoE damage is inept.\
Flash is powered by strength and weapon power, cannot crit, and cannot be boosted in any other way.
Also, Sword Oath!
Does poorly in drawn out fight, and is ill-equip at making them end faster.
Very, VERY bad design.
Can stunlock things for the longest time. Stunned enemies can't hurt you, but GCD will prevent you from making other actions if you intend on stunlocking for the max 10 seconds.
Anti-physical
EDIT: Oh I forgot! Additionally, because they don't have a frontal cone, this leads to some thinking some garbage such as tanking with things backstabbing you, when in fact even as a PLD you have to keep all the enemies in front of you. You cannot block or parry anything from behind. Guess how this affect Warriors and DRKs who just don't get it. . . .

I'd go with Warrior first. They get their tank stance at 30. They can sustain themselves. They deal reliable damage, not that it should matter to tanks like paladins, because damage powers your lifesteals. Overpower reaches wider and further than flash, and if your not confident in managing your TP, then cross class flash. It does drain the most TP of the tanks. General purpose, can reduce all damage. Thing is that without Inner Beast at 35, TP management will be an issue. Best way to deal with it is to do all you can to make sure there is no way the DPS can get threat the moment you cool off. Don't conserve Berserk at all. Also do not conserve wrath stacks, when you get to 35; there's no reason for it. Don't conserve bloodbath.

Dark Knight may be a good choice if you can manage the MP. Without MP you are absolutely shut down. It's strength and issues are similar more to the paladin. They rely on long CDs for defense. Has poor self sustainability vs multiple foes. Poor design It cannot synergize certain CDs because that will sabotage yourself. Regenerating MP after 38 requires being hit. It relies too much on getting hit while tanking, so enemies that attack slow will give you a hard time with the class. Is anti-magic. It's a disjointed mess.

Remember. Hit EVERYTHING, preferably all at the same time. Keep control of your resources. That doesn't mean conserve BEFORE you establish threat. Equip STR so that you can actually outthreat players better geared than you. Summoners will ALWAYS AoE. Don't follow the flash twice trend of failure like a robot, do more to maintain control. Do not EVER use provoke to start pulls. Do not EVER try to save the combo between pulls (for example not starting a pull with tomahawk cause you wanted to use butcher block before the combo expires).