The sooner, the better, to start collecting the PCG
If a face-up Level 5 monster you control is destroyed by battle, or leaves the field by an opponent's card effect, while you control this monster: You can add to your hand or Special Summon, 1 Level 5 monster from your Deck
These stats aren't spectacular, but Mewtwo's second ability, Barrier, can bring the game to a grinding halt
Pick up a deck, chase that Holo , and join the community of fans whove been keeping the game alive for decades
Other than Spike Feeder, of course which breaks even
But when you need a board wipe, you can use the Exude Toxin omen, dropping a powerful -X/-X effect that wipes out smaller non-dragon creatures