msem-instigator

{U}, Put a travel counter on Endless Discoveries: Draw a card. This ability costs {1} more to activate for each travel counter on Endless Discoveries.
{3}{U}{U}, Sacrifice Endless Discoveries: Return target instant or sorcery card with mana value less than or equal to the number of travel counters on Endless Discoveries from your graveyard to your hand.

At the beginning of your precombat main phase, choose one —
• Artifact spells cost {1} less to cast until your next turn.
• Nonartifact spells cost {1} more to cast until your next turn.

Trample, haste
Thriving Hydra enters the battlefield with four +1/+1 counters on it.
When Thriving Hydra enters the battlefield, for each other creature you control, put X +1/+1 counters on that creature, where X is four minus its power.
Whenever Thriving Hydra attacks, double the number of +1/+1 counters on each creature you control.

Choose one, then choose another for each card named Unraveling in your graveyard.
• Counter up to one target spell.
• Scry 2, then draw a card.
• Up to three target lands your opponents control don't untap during their controller's next untap step.
• Creatures your opponents control get -4/-0 until end of turn.