Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)
Tromokratis is a mono-blue voltron beater that suits up an evasive 8/8 and crashes in for big chunks of commander damage. Ramp into the seven-drop, protect your board with counterspells and bounce, and use the near-unblockable text to push through lethal hits. You typically win by connecting two or three times with buffs and trample/double-strike effects.
Built-in hexproof while not attacking dodges most targeted removal
Effectively unblockable in practice since opponents rarely have enough creatures to gang-block
Cheap to recast relative to its impact, and a single connection deals huge commander damage
Mono-blue gives access to the format's best counters, card draw, and protection
Folds to board wipes and edicts that ignore hexproof
Loses hexproof the moment it attacks, opening it to combat tricks and instant-speed removal
Token swarms and Fog effects can chump or stall it since 'all creatures must block' is easy when they have one creature
Mono-blue lacks efficient creature removal and struggles against go-wide boards
Mono-blue's premier blue catch-all to clear blockers or reset the board before swinging.
Lean into cheap unblockable enablers and double-strike effects (Rogue's Passage, Aqueous Form, Berserkers' Onslaught) so you need fewer connections, and add protection like Heroic Intervention-style mono-blue options such as Slip Out the Back or Snakeskin Veil for combat. Tighten the ramp suite (Sol Ring, signets, Sword of the Animist) to deploy Tromokratis ahead of curve, and round out with a counter package to defend it from removal and shut off Fogs or sweepers at key moments.