Applying Buffs		Buffs will not be applied (When target has below debuffs)	Buffs will be removed (Even when target has Debuff Immunity Bestowal)
Immunity Bestowals	Debuff ATK Interference Damage Over Time Stat Weakening	Prevention not possible (While immunity is active, prohibitions can still be activated)	Nullifier not possible
Purifications	Purification Binding Weakening Pain	Prevention not possible (Even when activated, prohibitions cannot be removed)	N/A
Reflections Counters	Debuff Reflection Reflections Counters	Buff Prohibition	Nullifier (Debuff Reflection cannot be removed)
Barriers	Barrier Regeneration Barrier	Buff Prohibition Protection Prohibition (Regen. Barrier cannot be prevented)	Nullifier (Protection Prohibition Regen. Barrier cannot be removed)
Healing	Bloodsucking Healing Masochism Regeneration Bestowal	Buff Prohibition Healing Prohibition	Nullifier
Miscellaneous	Stat Boost Bestowals Taunt	Buff Prohibition	Nullifier

 

Applying Debuffs		Debuffs will not be applied (When target has below buffs)	Debuffs will be removed (Even when target has Buff Prohibition)
Stat Weakening	Curse ATK Reduction DEF Reduction Incoming DMG Boost	Debuff Immunity Bestowal Stat Weakening Immunity Bestowal Debuff Reflection	Purification Weakening Purification
Attack Interference Effect	Blind Charm Freeze Shock Silence Stun	Debuff Immunity Bestowal ATK Interference Immunity Bestowal Debuff Reflection	Purification Binding Purification
Damage Over Time	Bleeding Burn Decomposition Exsanguination Poison	Debuff Immunity Bestowal DoT Immunity Bestowal Debuff Reflection	Purification Pain Purification
Prohibitions	Buff Healing Protection	Debuff Reflection (While prohibition is active, immunity bestowals can still be activated)	Removal not possible
Nullifiers	Nullifier Protection	Debuff Reflection (Even when activated, debuff immunity cannot be removed)	N/A
Miscellaneous	Concentrated Fire	Debuff Immunity Bestowal Debuff Reflection	Purification

Long story short: Debuff Reflection > Prohibitions / Immunity Bestowals = Nullifiers / Purifications > Other debuffs / buffs. While Prohibitions are active, Purifications can removed debuffs except prohibitions.  Likewise while Immunity Bestowals are active, Nullifiers can remove buffs except Debuff Reflection, and Immunity Bestowals. Examples：

• Applying Nullifier to Astrid with Debuff Immunity Bestowal, Regeneration Barrier, Taunt, and Regeneration Bestowal →Regeneration Bestowal, and Taunt will be removed, but Debuff Immunity Bestowal, and Regeneration Barrier will remain
• Applying Nullifier to Iris with Debuff Immunity Bestowal, Barrier, Taunt, and Charm Counter →Barrier, Taunt, and Charm Counter will be removed, but Debuff Immunity Bestowal will remain
• Applying Nullifier to Granhildr with Debuff Reflection, Debuff Immunity Bestowal, Barrier, Taunt, and Regeneration Bestowal →Nothing will happen
• Applying Buff Prohibition to Astrid with Debuff Immunity Bestowal →Buff Prohibition will be activated and Astrid will not get any new buffs
• Applying Buff Prohibition to Granhildr with Debuff Reflection →Nothing will happen
• Applying Debuff Immunity Bestowalm, and Regeneration Bestowal to Astrid with Buff Prohibition →Debuff Immunity will be activated, but Regen will not be activated
• Applying Purification to Astrid with Buff Prohibition, Charm, and Curse →Charm, and Curse will be removed, but Buff Prohibition will remain