Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Cruel Ultimatum

Target opponent sacrifices a creature, discards three cards, then loses 5 life. You return a creature card from your graveyard to your hand, draw three cards, then gain 5 life.

Inspired Ultimatum

Target player gains 5 life, Inspired Ultimatum deals 5 damage to any target, then you draw five cards.

Violent Ultimatum

Jegantha, the Wellspring

Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
{T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.

Jodah, Archmage Eternal

Flying
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Chromanticore

Bestow {2}{W}{U}{B}{R}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying, first strike, vigilance, trample, lifelink
Enchanted creature gets +4/+4 and has flying, first strike, vigilance, trample, and lifelink.

Titanic Ultimatum

Until end of turn, creatures you control get +5/+5 and gain first strike, trample, and lifelink.

Conflux

Search your library for a white card, a blue card, a black card, a red card, and a green card. Reveal those cards, put them into your hand, then shuffle.