1. Cast Mana Drain to target.
2. During draining, shift + any order.
3. Wait Mana Drain stop.

Compared with him:
1. Pick any other hero which has channeling ability.
2. Cast its channeling and does step 2-3.

Lion does nothing but stands still. The other hero follows its orders.

Lion's orders should not be cleared just like him before September 06, 2016 Patch.