Tips for final boss? (SPOILER WARNING)

[mr. mudkip4]

Before you say anything, no I do not mean Satell, Hired Wizard, or Satell Transformed, I mean Creator. The one that blocks all incoming explicit damage. My primary build, which was spiked armor with about 60k defense does basically nothing

[Elgareth]

His shield doesn't last forever. You'll need means to survive until his shield runs out.
(I did him back when you could easily perma-petrify and stack poison.)
I'd say the usual Experts Pajamas, Thunder Whip, Crown of Life, Synergizer at +15 each should easily do the trick. Some revival potions just in case and done.

[Hamster's Rage]

Did it with +15 Spiked armour + 15 Crown of Life + 15 Syngergizer for fast healing cooldown

You only take damage if the boss has OMNIDAMAGE buff which ignores the spiked armour
Keep your familiar behind if he does not have the damage buff.
When the damage buff comes on , juggle between your familiar and yourself to take turns taking damage.
If done right , you will almost never die.

When his OMNISHIELD is off , hit MAJOR TIME DILATION and cast everything.
Reset time if his shield is on or if your spells are on cooldown

Good luck!

[Wraith_Magus]

OK, here's what worked for me - I prefer using multiple equipment sets and switching between them rapidly, and I'm going to just say get everything to +15 first if at all possible.... But unless you're doing some post-game stuff that increases the difficulty even further, this much is already ludicrous overkill, so you can slack on a few things. (By which I mean +13 instead of +15, not +1.)

Go to your spellcrafting. Use anything that reduces casting time on spells like heal. Use jewels that increase duration on spells like absolute and petrification (these still work through omnishield). Use spell power increasing jewels on longevity and stoneskin.

Clear your boosts. Put everything into life and earth. Put leftovers into mind to mitigate misses if that's a problem, otherwise air to get a few more hits in.

In your pouch, bring the clever pumpkin, take some stun runes (these work through absolute defense), potion of vitality, a potion of sharpness (why not get crits), a revitalizer or two set to be used at 30% or less HP, and a potion of revival or two for safety's sake.

Set 1: Killer set. Switch to this whenever omnishield is down. This can be your spiked armor build. I also just use my divine rapier + master ninja gear + synergizer + boots of agility to get to a 0.006 attack delay and over 100% crit rate and do 3 million damage per second with melee attacks alone, which I find faster than waiting for the boss to hit me.

Set 2: Pre-combat set. Make a wand of fire, wand of water, gale staff, and optionally a wand of poison. Wear an expert's pajamas, synergizer, and optionally a mana geode. Manually cast major time dilation, then start rapidly going through your buffs, casting all the important buffs (stoneskin+, strength+, longevity+, haste+) so that they have as much duration as possible, and show up as having duration that you can watch on the bottom left of the screen before you start the boss battle. Switch wands to match the buffs you're casting (I.E. wand of water before casting longevity+, because that doubles the amount of HP you gain.) You should now have around 200-400k HP to tank damage with.

Set 3: Entering battle set. This doesn't matter much besides that it has alchemist's cowl to give +80% power of pouch items. "Buff" items are used at the very start of battle, so even if you only enter battle with the alchemist cowl, it still buffs their power and duration. With the potion of vitality, you should now have 6-10k HP regen per second. Feel free to equip the tunic of extravagant health for the memes.

Set 4: Durability set. Electric tuner + robe of mass healing + synergizer + crown of life. Electric tuner increases the power of energy shield, which divides incoming damage by 73% with the tuner (up from 53% without the tuner.) (Combined with cowled pumpkin, this reduces damage by 77%.) This is not defense/"shield icon", so this and the guard spell work against omnidamage. (I reduce his damage to below 2k even with omnidamage on.) Alternately, you can use thunder whip to try to paralyze the boss repeatedly to slow their attacks down to 1/4 speed. Robe of mass healing and crown of life maximize healing. (29k healing every 5 seconds with wide major heal.) You should be able to out-heal the damage without needing items for an indefinite period of time.

I also have two synchro boards - "healy" for durability, where life, water, and earth are in three columns in that order. (+4% spell power per 10 levels is WAY more than it sounds. Difference between 200k HP and 300k HP with longevity+.) "Killa" for max damage, with wind/death and water mixed to reduce cooldowns.

Reset time then turn just time dilation on while fighting the boss. Switch to the durability set for as long as absolute shield is on. When it's about to go down, turn on major time dilation, switch back to pre-combat for a second, use fire and poison wands to cast some extra attack/defense buffs, then when absolute shield is down, switch to your killer set. If need be, switch back if absolute shield comes back up, and watch the durations of your super-buffs. Switch back to the pre-battle set to recast longevity+ with the wand of water on (and other expert pajamas buffs) so your health doesn't nosedive if you need to. Remember to have major time dilation ready to cast and punch it whenever you need more time, then reset time when you've finished.

Wide impending doom+ does ♥♥♥♥-tons of damage (281k even with energy shield up), so use your stun runes when the charge gauge on those get near full. You can also use it when he's about to use omni shield again. Note that there's a "stun immunity" buff that comes on, so if he wants to use omni shield twice in a row, there's nothing you can do about it besides switch back to durability set and wait him out. Omnishields after the first only last 15 seconds.

[Bob]

I went for a much simpler build. Use a weapon of your choice (I used wand of doom), Tunic of Extravagant Health, Alchemist's Cowl, Ring of Regeneration, and ensure that you have the buff potions equipped, especially Potion of Vitality. Accuracy, Alacrity, and Sharpness are also huge, as is the pumpkin that reduces damage.

If there's one thing that's vital here, make sure your Alchemist's Cowl and Potion of Vitality are at +15.

Set your boosts to Life and Holy. The synchro doesn't matter as much, but I went for damage reduction primarily.

With this setup, I have 35,000 health and ~2,200 health regenerated per second. The way the boss's attacks work, it just can't kill you. Impending doom, in my experience, sets your health down to a low number that is intended to force the next hit to kill you. With enough regen, your health recovers to the point that the next hit can't kill you.

With all of this, you just sit there and tank the boss's damage. Omnishield will fall off, you do some damage, it gets reapplied, so you wait until it falls off again.

I did choose Holy and Death for my elements, so it's possible that Primary Protection was giving me some extra damage reduction against Impending Doom.