Forum:Magical Undertaker vs Solemn

I have Solemn Warning and Solemn Strike facedown. I attack my opponent's facedown Magical Undertaker. 1. My opponent has no valid Undertaker targets in graveyard. Can I activate Warning to negate its effect? 2. How about Strike? 3. My opponent has valid targets, but does not wish to use Undertaker's effect. Can I activate Warning? 4. Strike? I ask this because apparently Flip effects are all mandatory Thechosenone124 (talk • contribs) 22:37, May 8, 2016 (UTC)