Dota – What causes the tower to target your hero

The shield blocks 400 damage regardless of magic resistance.

The 30% Magic Resistance is calculated everytime,as it is passive.

So, for the Fingers of Death Example :

If you dont have the shield activated, it will deal -30% damage. If you do, it will still dealing -30% damage, and the rest of the damage will be used to lower your "shield" ammount of Magic Block.

Lion's ultimate info can be found here

Level 1 : 500 Damage - 600  With Aghanim's
Level 2 : 650 Damage - 800  With Aghanim's
Level 3 : 850 Damage - 1025 With Aghanim's

So, 30% Magic Res. would lower the damages to:

Level 1 : 500 - 150 = 350 Damage Or 600  - 180   = 420   With Aghanim's
Level 2 : 650 - 195 = 455 Damage Or 800  - 240   = 560   With Aghanim's
Level 3 : 850 - 255 = 595 Damage Or 1025 - 307.5 = 717.5 With Aghanim's

So, ignoring any extra Magic Defense that the heroe may have, you would be able to completely ignore the ultimate's damage only if he is at Level 1, and without Aghanims.

Otherwise, you would take some extra damage.

Hope it Helps.

Source : Self tested @ Dota 2 with Friends.

From the Dota 2 wiki:

Experience in DotA 2 is given by a unit on the enemy team that dies.

• Experience is equally shared by all allied heroes in a 1500 range.
• Hero kills outside of 1500 range will give experience to the killer. (I.e. Sniper's Assassinate, Invoker's Sun Strike, Zeus' Thundergod's Wrath or any summoned unit - Lone Druid's Spirit Bear, Nature Prophet's Treants, Broodmother's Spiderling and Spiderite)
• Denying an allied Hero does not grant experience to the enemy.
• Denying lane creeps grants 25% of their usual experience to both the enemy and the ally.
• Denying a player-controlled unit does not grant experience to the enemy or the ally.
• Neutrals killing lane creeps is considered the same as the enemy creeps killing them—it's not a deny, and gives full XP. You must deny the creep yourself to deny its XP.
• Neutral creep deaths grant experience to any nearby hero, regardless of the team that gets the last hit.
• Heroes take their share of experience even after level 25, even though they cannot use it.
• Observer Wards grant 100 experience when killed
• Ancients and Roshan acts as Neutral creeps with shared experience to all heroes within 1500 radius
• Bounty Rune grants experience to the hero that activates the rune (25 base exp + 7 exp/min)
• Hand of Midas active ability grants 185% of the transmuted creep's experience bounty to the hero that activates the item
• Tome of Knowledge active ability grants 500 exp to the hero that activates the item plus an additional 135 exp for each tome used by the team.