Michael Krumbs GP Charlotte 2005 winning list paints the picture well: Creatures (22) Lands (18) Spells (20) Sideboard Few cards have been involved in as much evil and just plain not playing Magic as Golgari Grave-Troll
Level 4, the highest power bracket, has "the strongest cards you can play in Commander and many cards players don't want in their game"
General Kreat, the Boltbringer General Kreat, the Boltbringer is an excellent addition to the impact cards
Emblems are permanent and unremovable
The spell that does so, Awaken the Blood Avatar, serves as an Edict for all opponents, however, and the Avatar himself can quickly burn down the whole table with its attacks, making the sacrifice worth it in a dedicated deck
These cards affect all players equally, demanding that you break the parity to make them worthwhile