Can Assassins be turned into a fighter?

Before I start I mean the AD assassins not the AP ones, so sorry

for example is an assassin, she has high mobility, cc and high burst/DPS and sustain. She can be built with lethality or just as her ad items, and deal tons of dmg either way. too, she can be built full ap, or go the off tank route and just buy these for her damage items .

But it got me thinking, can the other assassins be built off tank? and still do their job properly?

For example take he has high burst with his passive bleeding the enemy and his Q critting if the enemy is within the inner circle. But instead of going lethality, could he go ? I tested this in a practise, he life steals quite a bit but only from his autos, the rest of his kit does decent damage, his Q followed by an aa hits much harder because of the sheen empowering his aa. All in all it seems viable. Just wanted others opinion on it before I actually try it out. [slayer-jinx-wink]