Undead of Angmar is notable because it is one of few cards than can decrease the Ring-bearer's resistance (With other notable cards being Throne of the Dark Lord and Saruman, Master of the White Hand), potentially making corruption much easier. It also synergises with cards that monopolise off low resistance companions (Ulaire Cantea, Black Assassin; Horribly Strong; Frenzied Attack). It only affects wounded companions however, so it works very well with Ring-bearer wounding effects (Gollum, Dark as Darkness; The Witch-King, Lord of the Nazgul; Resistance Becomes Unbearable; Morgul Orcs).

The second effect of Undead of Angmar is doubly beneficial: It gives the minion two exertions (+4 strength with its enduring ability) and provides another Wraith for its first ability to spot. It can synergise particularly well with Covetous Wisp and Barrow-Wight Stalker, with the former adding burdens and the latter protecting it from non-skirmish wounding, which helps protect it from being finished off after its two exertions.

• Low resistance Ring-bearers
• Low resistance companions
• Low strength companions

• Skirmish wounding (Gandalf, Powerful Guide; Aragorn, Guide and Protector; Don't Follow the Lights)
• High strength companions (Durin III, Grimbeorn, Elladan)
• Burden removal (Jarnsmid, Barding Emissary; Golden Perch Ale; Shadowfax, Greatest of the Mearas)
• Resistance increasing effects (Salt from the Shire, Phial of Galadriel, Measure of Comfort)

• http://lotrtcgwiki.com/forums/index.php/topic,7895.0.html
• http://lotrtcgwiki.com/forums/index.php/topic,430.0.html

• Benefits from any cards targeting minions - Ulaire Otsea, Lieutenant of Morgul; Nazgul Scimitar; Houses of Lamentation; Gothmog, Morgul Commander etc.