Is making custom MTG cards legal
While its occasionally a part of various infinite loops, its most common application is as a value card, bringing back cards like Kitchen Finks, Vendilion Clique, Wall of Omens, and sometimes Blade Splicer
The ones that arent are doing it on purpose
Many of the cards in the deck deal with adding these counters, plus plenty of +1/+1 counters to your creatures, so you can bet that there are tons of ways to proliferate all your counters up to even higher levels and to keep your opponents constantly losing life through either combat or radiation
I would try and judge as you draft whether youre getting more powerful two-drops, or more copies of Aerith Rescue Mission, Rydias Return and The Crystals Chosen
This feels like a card better suited for a Soldier Typal deck, in all honesty, but the power boost can get Vincent and Bugenhagen going when needed