The second and third abilities of Champions from Beyond don't care what happens to those creatures after you attack with them
After all, the 5 colors of Magic are the core design that made the game so popular in the first place
EX6-028 R Digimon Lv [Counter] Blast Digivolve (One of your Digimon may digivolve into this card without paying the cost.) [On Play] [When Digivolving] Recovery +1 Deck [All Turns] [Once Per Turn] When a card is added to your security stack, return 1 of your opponent's Digimon with as high or lower a level as the number of your security cards to the hand
Based on the latest market prices tracked on TCG Stacked, Onix is worth about $0.43 USD
This answer provides examples of situations where having a larger deck might not be a strict disadvantage
A few examples that tend to show up on most wanted lists include Doubling Season (anime alt art), Smothering Tithe with a manga-inspired design, or perhaps Finneas, Ace Archer if it appears in a special release