Kaldheim

Youthful Valkyrie | Creature | Angel | Flying Whenever another Angel enters the battlefield under your control, put a +1/+1 counter on Youthful Valkyrie. | Anna Steinbauer

Clarion Spirit | Creature | Spirit | Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying. | Anastasia Ovchinnikova

Avalanche Caller | Snow Creature | Human Wizard | {2}: Target snow land you control becomes a 4/4 Elemental creature with hexproof and haste until end of turn. It's still a land. (A creature with hexproof can't be the target of spells or abilities your opponents control.) | Mathias Kollros

Bloodsky Berserker | Creature | Human Berserker | Whenever you cast your second spell each turn, put two +1/+1 counters on Bloodsky Berserker. It gains menace until end of turn. (It can't be blocked except by two or more creatures.) | Gabor Szikszai

Frenzied Raider | Creature | Demon Berserker | Whenever you activate a boast ability, put a +1/+1 counter on Frenzied Raider. | Lius Lasahido

Fearless Liberator | Creature | Dwarf Berserker | Boast — {2}{R}: Create a 2/1 red Dwarf Berserker creature token. (Activate only if this creature attacked this turn and only once each turn.) | Zezhou Chen

Fynn, the Fangbearer | Legendary Creature | Human Warrior | Deathtouch Whenever a creature you control with deathtouch deals combat damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.) | Lie Setiawan

Koll, the Forgemaster | Legendary Creature | Dwarf Warrior | Whenever another nontoken creature you control dies, if it was enchanted or equipped, return it to its owner's hand. Creature tokens you control that are enchanted or equipped get +1/+1. | Bram Sels