Unstoppable means that your damage can't be stopped or interrupted during the animation by things such as Flash. What you'll be using for 90% of the game when fighting. This is doubled if Yorick is below half hp. Q: Last Rites Yorick empowers his shovel, making his next basic attack making it unstoppable, granting an additional 50 attack range, dealing bonus physical damage, and healing Yorick for 12-82 (based on LVL) hp. Then walk to mid and create 4 more, etc.)
EX: Spawn 4 top, and let them aggro the creeps. (NOTE: You can have 4 in each lane,though. Note that you can only have 4 graves at a time, as well as 4 mist walkers in the same proximity of eachother. Passive: Shepherd of Souls Yorick makes a grave for every enemy champ, large monster, and 12th/6th/2nd (based on lvl) non-champ enemy that dies near him.