The reason there is only 1 "Full Speed Warrior" is that while "Synchro Fellows" can play through interruptions in combination with "Psychic Reflector," "Full Speed Warrior" uses up your Normal Summon and might not be able to play through, so 3 copies of "Synchro Fellows" are adopted
Its a 5/4 for 4 mana with relevant static abilities that stops life gain as well as damage prevention
For example, Become Immense technically has a CMC of six, but if you've ever played with or against Death's Shadow Aggro, you'll know that it is most often cast for one mana, so for the sake of our calculations, we count it as one CMC rather than six
If it is a "Dangan" monster, you can reveal it to place 1 Bullet Counter on a face-up card you control that you can place a Bullet Counter on.
Now do they attack and lose that monster, or hold back and leave your life points intact