Life Transference was introduced in Xanathar's Guide to Everything (Page 160) and allows a caster to take necrotic damage to heal another for double the damage taken. Unique in being the only healing spell on the Wizard's spell list.
It was Errata'd in 2020 with "You take 4d8 necrotic damage, which can’t be reduced in any way."
This clearly applies to resistances and immunities.
However, the Abjuration Wizard has an Arcane Ward that "takes the damage instead".
- If an Abjuration Wizard has an Arcane Ward active, does the Ward take damage or is it bypassed?
- If the Ward takes damage, how much is healed by the ally?
Similarly, Oath of Redemption Paladins have an Aura that lets them take damage their ally would've taken, which also "can't be reduced in any way."
- Can Redemption Paladins take the Life Transference damage in place of the caster?
- If the Paladin can take the damage instead, how much is healed by the ally?
In other words, is some other entity taking this damage for you considered "reducing" it? And if not, does this affect the healing done?