At the beginning of combat on your turn, Irma becomes a copy of up to one other target creature you control, except her name is Irma, Part-Time Mutant and she has this ability. Then put a +1/+1 counter on her.
Each combat, Irma copies your best creature you control and stacks a +1/+1 counter, so you build a board of strong creatures and turn Irma into a growing second copy of whatever matters most that turn. You ramp into and protect key value creatures, then either swing wide/tall or chain copy effects and ETB triggers for value. The +1/+1 counters make her a credible threat even when copying small utility bodies.
Free clone every combat lets her mirror your strongest or most synergistic creature without spending cards
Steadily accumulates +1/+1 counters, so she grows into a real beater regardless of what she copies
Works with any creature you control, giving huge flexibility and resilience to board states
Mono-blue gives access to elite counterspells, card draw, and tutors for consistency
Mono-blue lacks efficient removal and struggles against resolved problematic permanents
Copy only triggers in combat on your turn, so she's slow and does nothing the turn she enters
Heavy reliance on having a good creature already in play; an empty or wiped board makes her ability worthless
Commander-damage and counter strategies fold to single-target removal and board wipes
Legendary Creature — Human Mutant Shapeshifter
