I am new to playing Magic, and I'm trying to teach my 9 year old daughter and father what I know (which needs lots of clarifying). I've read several of the the questions posted on this forum and have learned a great deal. So, I'd like to post one of my own concerning the sorcery Declare Dominance. Here's the situation:
I attacked my opponent with Gravewaker (5/5) and destroyed their Sun Sentinel (2/2) during the combat phase. I then decided to cast the sorcery Declare Dominance during the second main phase and target my Gravewaker making it a (8/8). The directions on the Declare Dominance card state that all creatures able to block it this turn do so. I interpreted this to mean that all creatures my opponent had under their control, which were not tapped, were required to attack my Gravewaker (8/8). So, does this create a second combat phase? I assumed it did, and I made my opponent's Pyromantic Pilgrim (3/1) block my Gravewaker (8/8), which I in turn destroyed. Was this a correct use of the Declare Dominance sorcery?