Ice shards is a spell designed to limit the mobility of the enemy team, but it also has the potential to ruin something your teamate wants to do. This high risk, high reward gameplay is very exciting to me.
Tusk being a strength hero is fun for me because it puts him on the frontline of every fight, always in the middle of the action.
Glimpse is a spell that repositions the enemy to where they were 5 seconds ago, so it requires a lot of awareness to remember where they were and where you want to put them. Similar to shards its a very high risk , high reward spell.