Transmute (, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle
There are infinite combos that outright win you the game, like with Walking Ballista, but Heliod can be a centerpiece of devotion decks, +1/+1 counters, lifegain decks, and enchantment-based decks
Unfortunately, that flavor doesnt translate to power, as Phoenix of Ash is definitely far too slow for any of the Magic formats its legal in
Interaction If Im running blue, I do like to have a few counterspells in the deck for the occasional emergency, either to stop someone from killing me or to stop someone from stopping me from killing them
Creatures you control with three or more +1/+1 counters on them have haste
The fact that it needs only 3 Energy vs 4 Energy required for OP EX cards means that it can use the opponents attacks even before they are ready with theirs