Q re titan and earth resist

[MaFi0s0]

I forget the name but he has a move that tanks should use a Cooldown for, is this earth damage? If you were made of gil would it be worth equiping jewellery with earth resist materia or putting earth resist in crafted gear?

[Anova]

I believe the skill is called "tulmult" and is an aoe damage to the entire party. Earth resist jewelry/materia is fine, but you will most likely be wearing a majority of darklight gear (or maybe better), which does not have slots or resist stats. Consider using an earth-ward mega potion instead. Your tank will have to time it at the time the skill is used (near the end, when titan is launching 8 of the attacks in succession).

[Maelwys]

I believe the skill is called "tulmult" and is an aoe damage to the entire party. Earth resist jewelry/materia is fine, but you will most likely be wearing a majority of darklight gear (or maybe better), which does not have slots or resist stats. Consider using an earth-ward mega potion instead. Your tank will have to time it at the time the skill is used (near the end, when titan is launching 8 of the attacks in succession).

[Disclaimer: I've tanked HM Titan but wouldn't be an expert on tanking him in Turn 5!]

For Tanks the skill you'll want to use a cooldown for is "Mountain Buster". This is a VERY high damage cone.
It's Earth damage (like ALL of Titan's moves) and you only need to worry about it in the last phase of the fight (immediately after the phase-transition AoE from the heart phase, and then after every landslide thereafter).

After every other Mountain Buster he will do a Tulmult (Multi-hit Footstomp) that hits the entire party and is the only damage that's unavoidable for anyone besides the Tank.
Over time he gradually performs more hits with each Tulmult, so your healers will get more and more taxed as the fight drags on.

The MB hit requires quick/precasted ST heals on the Tank, and Tulmult requires quick + uninterruptable AoE heals on the rest of the party.

The problem isn't usually the damage that Mountain Busters do - if you are wearing decent gear (Over 5200HP is a good ballpark for a PLD - anything higher is a bonus) it won't kill you by itself. It's that it happens immediately after the Bombs, and alongside Titan's normal autoattack hits. There are three possible arrangements of bombs, and one of those arrangements in particular makes it quite tricky for a Tank to dodge all nearby bombs completely. If you have to "eat" one bomb and then get hit by a Mountain Buster afterwards, it's Faceplant time unless you are very lucky and/or your healers are exceptionally good. So it's good practice to save Damage Reduction cooldowns to pop them before MB just in case... or even save 'Hallowed Ground' for the occasions when you have to eat a bomb.

The generally-held perception is that a good Paladin should also be using "Flash" before the MBs to inflict blind on Titan, since MBs (and any subsequent Tulmult hits) will then have a chance to miss. I suppose you could pop an Earth Potion too if you had it available... but you only have a certain amount of time to precast stuff, the cooldown for the potions is longer than the time between MBs and the resistance buff they provide is quite weak.

See this chart for any further queries