Raid - Wazahamimaru | Fate Grand Order Wiki

Boss Statistics

Active Buff		Increases resistance to Arts cards by 50%
Skills		Reduces the defense of all enemies by 20% for 3 turns
NP Effect		Deals around 6000-6500 damage (3BP) to all opponents and seals skills for 1 turn

Tamamo no Mae Statistics
	HP	20,000 - 600,000
	LVL	15 - 65
	Class	Caster
	Skills	Has access to all three of her skills
	NP	Eightfold Blessings of Amaterasu: Small heal and team NP charge

Battle 1/2	15,000 Lesser Oni	30,000 Vile Oni	15,000 Lesser Oni
Fatal Battle 2/2	6,000,000 Wazahamimaru		600,000 Tamamo No Mae

Do not forget: Exploit wave 1 to generate as much NP gauge as possible
Tamamo isn’t very dangerous, but if you let her NP she will put pressure on your defensive cooldowns as it increases Wazahamimaru’s NP gauge.
Keeping Tamamo alive for a while can be useful for NP generation. Tamamo has a high hit count which means Servants will gain a lot of extra NP gauge if they're attacked by her.
Furthermore, Tamamo does not possess an Arts protection buff. Masters can unload their NP on Wazahamimaru and then use their Arts cards on Tamamo to generate NP gauge normally.
Take out Tamamo for her drops before Wazahamimaru dies either way.
Wazahamimaru’s skill is actually rather painful and combined with his NP, even lethal.
Despite his Arts protections, Wazahamimaru’s class and traits make him extremely vulnerable to Euryale and to a lesser extent, Orion.
A max ascension, and strengthened, Euryale with the blue bean consumable can spam her NP repeatedly, stall for days and do some ridiculous damage to Wazahamimaru with her NP.
ST Archers and Berserkers are your best damage-dealers here. Note that Gilgamesh does not gain additional damage on his NP against Wazahamimaru.
Try to drain Wazahamimaru’s NP bar or disable him once with a full NP bar. This will result in one less NP provided Tamamo doesn’t charge his NP.

Try to field set-ups with two Servants that provide offensive buffs for one main DPS with Golden Sumo equipped.
But don’t leave the main DPS entirely undefended, especially if the DPS is a Berserker.
Ideally, a set-up would be Main DPS / Support / Offensive Hybrid or Main DPS / Support / Support.
Field additional Supports or Hybrids in the backline as generally the Main DPS will not fall first.
Abusing the Order Change ability of the Chaldea Combat Uniform is very effective if combined with Euryale or Orion. Swap the Servant in the third slot with someone in the backline for extra buffs, by stacking even more arts or damage buffs with blue beans, the initial NP can deal millions of damage to Wazahamimaru
A team-wide cleanse, or using the Rain of Isis from the Atlas Academy Uniform can be very useful in keeping your team alive here. Furthermore the Eye of Medjed’s cooldown reduction is very useful for reducing the waiting time between big bursts of damage from Euryale and Orion.