Mumei is tied with Sana for having the lowest base ATK of 0.8 or -20% ATK. However, Mio is the one who has the lowest natural ATK stat of 0.85 or -15% ATK. Mumei’s natural ATK skyrockets mainly due to her Civilization skill, and Sana’s Speaker of Space skill bumps up her natural ATK to 1.4 or +40% ATK. For Mumei’s main weapon, the extra damage from the Growth upgrade is reduced to 75% as well as still being divided by the number of projectiles. 2:24 nice catch, the hit limit for Mumei's main weapon at level 5 and above is 15. If there was a discrepancy, then the Wiki should put a note of it in the details. Extra damage from Anvil boosts and the Growth Upgrade are not affected by the damage modifiers from Mumei’s Friend skill that reduce weapon damage to 50%/65%/80% for levels 1/2/3 of the skill. Friend has a base attack speed of about 5 seconds and this attack speed is affected by Haste. This means that weapons with slow attack speeds, such as Curse Ball (base attack speed of 11 seconds) and Absolute Wall (stuck at an attack speed of 10 seconds), benefit the most from being duplicated by Friend. In the case of Absolute Wall and similar weapons, Friend does not share their attack speed limits. Friend is not affected by the Reverse Stamp, as well as the attack speed increases from the Haste Up Stamp and Cooldown -10% enchantments. Mumei’s special does not affect the Yagoos past 30 minutes, due to them counting as mini-bosses. Mumei’s special can defeat invulnerable enemies.
Here are a few other notes about Friend. Absolute Wall has a bit of a glitch with Friend. Two cutting boards spawn in the forward position when an Absolute Wall is created by Friend and the cutting board directly clockwise from the forward position is missing or in the wrong position. Curse Ball is gently thrown forward when used by Friend. This seems to reveal that the reason Curse Ball is launched forward when it spawns from the player is because it immediately interacts with the character. The actual attacks of the Snow Queens do follow Friend when they are activated by him, but there are no visual effects for those Snow Queens.
