Bioessence Hydra
Oracle Text
Trample
Bioessence Hydra enters the battlefield with a +1/+1 counter on it for each loyalty counter on planeswalkers you control.
Whenever one or more loyalty counters are put on planeswalkers you control, put that many +1/+1 counters on Bioessence Hydra.
Seems fair. 11/11 trample and gain 11 life.
Play a Jace, Unraveler of Secrets and this gets +5/+5. Have Doubling Season out and this would get +20/+20 instead.
If you can pull off this combo without being punched in the face you should win a medal of some sort.
Are you sure about that? The card also contains the "put that many" rule which would indicate that the hydra will get as many counters as there are loyalty counters on the new Planeswalker. The only thing I would be concerned about is whether playing a new planeswalker with X loyalty actually triggers the passive ability at all. The planewalker enters the battelfield with that many counters already so they are not technically put on it (at least not when the planeswalker is on the battelfield).
However, play Jace before, THEN the hydra, and it gets as many counters as the Planeswalkers have, so better play it after you played all your + abilities but before the - abilities
Whenever one or more loyalty counters are put on planeswalkers you control, put that many +1/+1 counters on Bioessence Hydra.
You add 3 loyalty counters, the Hydra gets 3 +1/+1 counters.