Maelstrom Nexus

+1: Until your next turn, creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures. −3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle. −7: Destroy all non-Dragon creatures. Sivitri, Dragon Master can be your commander.

Flying Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

The "legend rule" doesn't apply to tokens you control. Whenever another nontoken legendary permanent you control enters, you may pay 1. If you do, create a token that's a copy of it. That token gains haste. Sacrifice it at the beginning of the next end step.

T: Add C. 5, T: Add WUBRG.

Each other multicolored creature you control gets +1/+1 for each of its colors.

Whenever a creature you control becomes blocked, it gets +3/+3 until end of turn for each creature blocking it.

Choose up to one creature. Destroy the rest.

This land enters tapped. When this land enters, return a land you control to its owner's hand. T: Add WB.