Sample Collector

Collect evidence usually treats the graveyard as a one-time spend: exile a few dead cards, fire off a scry or a small effect, and move on. This creature turns that spend into a recurring combat engine. Every attack offers to exile cards totaling three or more mana value for a permanent +1/+1 counter, so the graveyard stops being a pile of spent cards and becomes a fuel tank that drains one swing at a time. The counter placement is the wrinkle worth sitting on: it targets any creature you control, not the attacker, so the growth can be redirected onto whatever needs the size (a lord, an evasive threat, a second body running unblocked). And the two impulses fight each other by construction. A graveyard payoff wants a full yard; a repeat attacker wants to keep swinging without pausing for the reservoir to refill. The more you attack, the faster you burn through the very resource the ability needs, so the card rewards a deck that restocks its graveyard as fast as it empties it. The optional wording matters too, letting you decline the evidence when the yard is worth more intact than a single counter is worth spending it on. That is the honest read of the 2/3 body: modest on its own, and relevant only in proportion to how much value your graveyard is willing to give up.