This clever loop thrives on a perpetual engine of growth and validation fueled by the interplay of life gain and token generation. It begins when you spark the cycle by gaining life, causing Light of Promise to place a +1/+1 counter on Herd Baloth. That sudden infusion of power triggers Herd Baloth to spawn a 4/4 Beast token, which in turn satisfies the chapter II/III ability of Thunder of Unity to drain your opponents and grant you life. That very chunk of life you just gained loops right back into Light of Promise to restart the entire sequence, compounding into an endless cascade of counters, tokens, and life-draining devastation.