Trauma Sliver

[Alterloth]

Trauma Sliver UUU

Creature - Sliver (uncommon)

Landfall - Whenever a land enters the battlefield under your control, target
opponent takes X cards off the top of his or her library and puts them into
the graveyard equal to the number of slivers you control.

1/1

[Chodie]

Slivers share they're abilities with others. It should be something like.

All slivers have,"Landfall - Whenever a land enters the battlefield under your control, target player puts the top X cards where X is this creature's mana cost."

Don't make X slivers. I would make it lands, cards in opponents hand, or the slivers