User blog comment:V0ldek/Yone, the Death's Debtor AKA Yasuo's brother/@comment-5035765-20131216213854/@comment-8225465-20131217145247

He has weeknesses, he is squishy and even if he builds tanky he loses armor and resists on ulti. He is also easily gankable because his invisiblity takes 4 seconds to take an effect after Yume's damaged.

Changed the true damage to magic damage, you are right, true damage from ult is enough for one champion.