Investigate effects that redirect damage to source

Ancient Adamantoise, Palisade Giant, Protector of the Crown, Empyrial Archangel, Pariah, Pariah's Shield, Saving Grace all extend ReplacementEffect rather than RedirectionEffect. Is this correct?

Either way, there's probably some room for refactoring to common classes (to inform players consistently) and adding tests (to be sure multiple replacements work properly)

Palisade Giant has a weird check about card names which I'm pretty sure is totally bogus but it might be a loadbearing hack to account for interaction of multiple permanents with this ability.

One interesting test case - Everlasting Torment (damage is dealt as though its source had wither)

_Originally posted by @xenohedron in https://github.com/magefree/mage/pull/13670#discussion_r2106077364_

Start by locating the listed card effects and comparing their ReplacementEffect and RedirectionEffect behavior. Inspect Palisade Giant's card-name check, then investigate interactions with multiple replacements and Everlasting Torment. Done means the effect classification and any shared behavior are justified, with regression tests covering the identified interactions.

Written by the indexing model from the issue text.