You'll still pay all costs for a spell cast this way, including additional costs
This way, the suggested decks will have more longevity
It can be risky, but its incredibly consistent, and it allows me to greatly reduce my creature count
Rikku, Resourceful Guardian allows you to force a creature through your opponents' blockers, as well as steal counters, and Lulu, Stern Guardian protects you by putting stun counters on your opponents creatures, as well as proliferating to keep them around
In a different color combination that would not have been much of an issue as control decks would gladly use a card like this to buy themselves time, and perhaps would do so now that colored mana is plentiful, but the beatdown decks that were in these colors were understandably reluctant to force themselves to count to twenty-five