If you do want to stick with the madness theme, considering heading toward Vampires, playing Falkenrath Gorger, and trying to loot your graveyard full of tribe members to reanimate with something like Living Death
It contains a single-player mode called Trainer Challenge which unlocks three theme decks (Born of Fire, Crushing Current, and Hidden Depths), a free versus mode Psychic theme deck (Mental Might), and online tournaments
(Equipment, Auras you control, and counters are modifications.) Whenever a modified creature you control deals combat damage to a player, search your library for a basic land card, put it onto the battlefield tapped, then shuffle
There are often pivotal moments where taking out a threat for even a turn or two can completely change the tide of battle during a Commander game
I have used him to get Ancient Den or Great Furnace to ensure I had those colors