Hydra Rampage (Modern)

Mana Ramp and one shot someone with Kalonian or Primordial.

Bioshift - for +1/+1 management such as saving counters if you get destroyed, or shifting them from someone onto primordial before opponent endphase so you can double them for your upkeep. or shifting counters onto your gyre sage if your hydra couldnt be protected from destruction you could leave 1, the spell would still go through on the hydra but you now have X mana added onto gyre sage.

Burst of Strength - self explainatory mainly. Combos well with gyre sage for doubling mana or double blocking.

Savage summoning - Wait until your opponent taps out mana before he ends turn to summon kalonian or primordial with flash on their turn so that you could double +1/+1 counters and swing on your next turn.

Hardened Scales - also very self explanatory. It might not seem as much, but with all the support cards in this deck you multiply almost exponentially. a big combo for only 4 mana is waiting for your opponent to end turn and with this enchant already out, you can savage summon for 1 mana, summon Primordial for 3 total mana, and he would come out with 4 +1/+1 Counters on the opponents turn so when its your turn, Primordial Hydra is 9/9 after he doubles and adds one more counter.

Enter the Unknown - land search, Scry, and also a +1/+1, very useful for the deck.

All in all SUPER fun deck. Ramp is super quick and you will daze people by how fast your hydras will grow.
(Disclaimer - IF YOU ARE NOT GOOD AT MATH, DO NOT PLAY THIS DECK)