While it doesnt have any other keywords that are great on large creatures like trample or menace, it does provide all permanents you control hexproof so long as youre the monarch
In the literal sense, Caetus is a clear winner)
All of this is piloted by either the face of the deck, Valgavoth, Harrower of SoulsValgavoth, Harrower of Souls, or The Lord of PainThe Lord of Pain, a card that seems to see a bit less play in the command zone
It is unreal powerful and turns close games into jokes
It can be built as a control deck that copies removal or combo focused on big spells like Time Warp and Jeskai Revelation
The unpredictability of manifest cards adds a surprise factor to your plays, especially when youre flipping face-down cards into powerful creatures