[missing some broken stuff from post modern horizons]
This is my no-budget, semi-competitive (tier 2ish) take on artifact Reyhan counters. It primarily focuses on the +1/+1 synergies of artifact creatures, similar to modern's hardened scales affinity, and aims to build up counters quickly on one or more creatures in a go wide/tall fashion. The power of the deck comes from the redistribution of counters via Reyhan's ability or modular effects. These effects give the deck its power, as we are able to take advantage of +1/+1 abilities such as crystaline crawler's to make mana, fathom mage, mindless automaton, or etched oracle to draw many cards, and walking ballista or triskelion to potentially kill our opponents. Most of these synergies are finite, however, there are several infinite combos within the deck which we'll discuss later on.
The deck's major weakness is that in order for it to operate properly, different functioning pieces are needed. We need cards that can distribute counters efficiently and quickly like steel overseer, arcbound ravager, hardened scales, and winding constrictor, but we also need a sacrifice outlet to fully take advantage of our namesake commander's ability. Even then, having a sacrifice outlet and creatures with counters isn't entirely where we want to be. We still want one of our payoff creatures like fathom mage, or hangarback walker to be threatening. Because of the diversity in operating pieces, we run several tutors for consistency. Whir of invention, chord of calling, and transmute artifact allow the deck to function more smoothly, but also have demanding mana costs. Even though the deck is primarily colorless, it's important to run proper fixing for the tutors. This deck is designed to play in a semi-competitive meta, where it's not uncommon to lose to a combo on turn 4-5, so expecting to have 3 blue mana by turn 3-4 is imperative, otherwise cards like whir of invention and transmute artifact are irrelevant. Note: crop rotation is in the deck almost exclusively to fetch gaea's cradle.
Tutors also allow us to search up combo pieces, if that's the kind of mood we're in. I created this deck to be more synergy oriented than combo, but sometimes winning is more important than flexing deck synergy. As previously stated, my particular meta isn't messing around, and a mikaeus/ ballista win is as acceptable as any other. Fetching up a two-piece isn't really in the spirit of the list, however, and both these cards work well in the deck independently of each other. Alternatively, a three-piece combo such as the available krark-clan ironworks/metallic mimic/animation module win might be a more rewarding. I'm sure there are also many combos with scrap trawler, but i can't be bothered listing/looking for them. The most fun infinite combo within the deck, in my opinion, is the one that doesn't even involve +1/+1 counters, though.
Like a hat on a hat, the additional sub-synergy of charge counters isn't really adding to the overall efficiency, but i had trouble finding additional artifact creatures that would have slotted seamlessly into this strategy, and decided to add a few charge counters cards instead because they work well with the already-present proliferate mechanic. Coretapper and magistrate's scepter work very well together, and the two coupled with a recurring proliferate mechanic like throne of geth, or just voltaic key/unwinding clock allow us to take infinite turns pretty easily. This isn't a two card combo, but it's definitely viable, and, in my experience, is a lot more fun than a mike and trike win. Another fun synergy is power conduit and phyrexian scriptures. The deck is pretty formidable solely as an aggro strategy, and wiping your opponent's creatures each turn will lead to easy win most of the time.
The last piece of the list is just 5 planeswalkers which i felt were strong enough to warrant a spot. Planewalkers are typically better in a slower meta, but the deck already uses proliferate, so they seem worthwhile. Karn, tezzeret the seeker, and tezzeret, agent of bolas are great value, while vraska and tezzeret, artifice master offer us a back-up wincon, and put a clock on our opponents. Vraska, and tezzeret the seeker, in particular, are good in our deck because they either work as a sacrifice device, or a means to fetch one. Because our deck is, more or less, an aggro deck, it can very difficult for many decks to deal with our planeswalkers without having removal. This at least makes them a little more worthwhile.
This deck is a work and progress, and i'm certainly open to any constructive criticism if anyone has ideas. Also, while this deck is budgetless, the most important pieces are on the cheaper side. It is not imperative to have the land suite shown here, nor is it imperative that you have a mana crypt, mox opal, or transmute artifact. I'm used to proxy cards, and playing against more competitive edh builds, but this strategy is perfectly fine, if not more fun and viable, as a cheaper variant within a more casual playgroup.