Arnaud, Seventh Army Sniper

Partner with Freyalise, Seventh Army Skald
(When this creature enters the battlefield, target player
may put Freyalise, Seventh Army Skald into their
hand from their library, then shuffle.).
Reach
Whenever a creature enters the battlefield under
an opponents control you may pay {r}{r}. If you
do Arnaud deals X damage to that creature,
where X is Arnaud's power
Whenever a creature an opponent control dies,
Arnaud gets +1/+1 until end of turn