We rock Tithe (which can get Plains or Mistveil Plains) and stuff like Solemn Simulacrum, Burnished Hart, Armillary Sphere, Palladium Myr, Pilgrims Eye, and more
DBS is another game Ozzie Collectables has recently taken on for weekly tournament events - check the full event schedule here
Split cards started out as two monocolour spells (colour A and B), then we got two multicolour spells with a common colour (AB and AC), then we got two of the same colour (A and A), then we got a return to multicolour splits again (AB and AC once more), then we got monocolour spells where you could only cast one side from the graveyard, one from the hand (so A then B)
Throw in haste and a potent gravebreak ability that grows the Academic, and you end up with a synergistic yet highly efficient threat
We dont have an errata to phasing here, though
If you are unsure as to whats unreasonable you could look up the card on the Pokmon TCG card database to get a ballpark range of where its HP is usually at