Notes & Combos
(Note the absence of Union Carrier; it is banned, but was the thing that made this deck)
The typical end board of ABC and CDI is this time complemented by one additional omni-negate/mild extender. This is a midrange deck that, in the best of days, lands on a Halqadon-esque negate board that very few decks can play through. Union Hangar is a one-card two interaction board with a Spot Banish, Float, and Omni negate, so hard drawing Union Hangar, Water Enchant/Rite of Aramesir, and/or Therion "King" Regulus (or a terraform) only compliments that strong core.
Turn 1 combo is simple: activate Union Hangar, Normal Summon A or B, equip Driver, Driver eff, attach A or B (opposite of whichever one you normal'd) then link Carrier, B CL1, A CL2, yadda, yadda, yadda. We're running a hefty hand trap package for interrupt on turn 2, 1x Cosmic Cyclone for Runick (although it's still a terrible matchup) and yeah!
Sadly, Union Carrier is being banned in anticipation of Spright. If the Master Duel Banlist goes unchanged - that is, we don't get more Terraforms, Prospis, or Adventure like in the TCG, ABC is, in my opinion, not worth playing. In this form, it's a solidly mid-range deck that's one or two support ED cards or Spell cards from being Tier 2/1 (I believe this unironically). But since Konami will never Errata Carrier to require two LIGHT Machine Unions to summon, this version of ABC is not legal in any YGO Format.