Trundle DOES NOT COUNTER YORICK. His passive gives him 2~6% HP per minion. that's around 30~ 60 HP per wave, or every 30 seconds. At level nine, his passive will be at around 4%. Melee minions will have aounnd 500 hp and Caster minions will have around 280+15*3 = 325 HP. This means he will heal roughly 500*0.04 + 325 * 0.04 = 20 + 14 = 34 HP EVERY 30 SECONDS.
Yorick's omen of damage heals 40% per DAMAGE DONE, which is roughly 200 (+1 per bonus attack damage) EVERY TEN TO SIX SECONDS. This means that Yorick is dealing 200 damage and healing 80 hp every 6 seconds at level nine, or dealing 1000 damage and healing 400 every thirty seconds. More with passive health regen, or cdr.
But Yorick has mana problems.
FALSE.
Yorick regens 6.5+(0.45) Mana per 5 and has max mana 265(+35) . At level 9 he will have a base of 10.55 mana regen per 5and 580 max mana. With tear he gets +350 Max mana and +7 mana regen per 5, and gives him +4 max mana per cast.
Yorick's red ghoul only costs 75 mana to cast.
This is without taking into account runes or masteries. In comparison, Nasus's soul siphon ability is just 14% lifesteal.
IN ORDER FOR NASUS TO REGEN 400 HP IN 30 SECONDS, HE WOULD HAVE TO DEAL 2857 DAMAGE, WHICH IS CLEARLY RIDICULOUS.
But yorick has a bad late game!
WHO KEEP SPREADING THIS PACK OF LIES? Yorick has a passive 0~20% bonus damage AND damage reduction. He has AOE slow, a long lasting speed buff to chase down runners, AND CAN ULT HIS CARRY FOR 75% OF HIS CARRY'S DAMAGE, CRITS INCLUDED. Nasus and trundle do not counter yorick, pick mordekaiser, swain, or cho'gath.
Link to thread here:
http://na.leagueoflegends.com/board/showthread.php?t=2365135